Sulfonated poly(arylenes) as hydrolytically and thermo-oxidatively stable polymers

ABSTRACT

Hydrolytically and thermo-oxidatively stable sulfonated polyarylenes include the structural element —X—Ar(SO 3 M) n -Y—. The aromatic ring carrying the sulfonic acid group is substituted exclusively by electron-acceptor bridge groups X and Y and, if applicable, by other non-electron-donor substituents. Their synthesis and application are also included.

RELATED APPLICATION

This is a §371 of International Application No. PCT/EP2006/002087, with an international filing date of Mar. 7, 2006 (WO 2006/094767 A1, published Sep. 14, 2006), which is based on German Patent Application No. 10 2005 010411.8, filed Mar. 7, 2005.

TECHNICAL FIELD

This disclosure relates to sulfonated poly(arylenes), methods of making the sulfonated poly(arylenes) and their applications.

BACKGROUND

The uses of ion-conducting materials in electrochemical applications such as fuel cells, dialysis cells, electrolysis cells and electrochemical separation methods, are limited by their hydrolytic and thermo-oxidative stability zones, which are often within a range below 100° C. However, for a number of applications, such as in the case of the fuel cell, it is advantageous to achieve higher working temperatures (approx. 100-200° C.). On the one hand, this requires less cooling for the fuel cell; on the other hand, the electric performance of the cell increases with higher temperatures, due to accelerated electrode reactions and reduced electrode contamination (e.g. due to CO from a reformer).

Higher temperatures, particularly in a water- and oxygen-containing environment, require chemically, thermally, thermo-oxidatively and hydrolytically stable materials.

At the moment, essentially perfluorated sulfonated polymers (e.g. Nafion®) are used, for example, in the area of fuel cell technology; these generally have a high chemical, thermal and thermo-oxidative stability, but are expensive and time-consuming in their manufacture and disposal. A more cost-effective alternative to perfluorated polymers is presented by membrane materials based on sulfonated poly(arylenes), such as poly(arylene ether ketones), poly(arylene ether sulfones) and poly(arylene thioether sulfones), which are currently being tested for fuel cells. (General references on the state of the art of fuel cells and suitable membrane materials, as well as the synthesis of the above-mentioned and other poly(arylenes), are indicated in the literature overview on page 78-81 of the application text).

In terms of structure, poly(arylene ether ketones), poly(arylene ether sulfones) and poly(arylene thioether sulfones) share the characteristic that at least one electron-donor bridge group (such as ether —O— or thio —S—) is bound to the sulfonated aromatic ring. Since the hydrolytic stability of the sulfonic acid group at the aromatic ring is impaired by electron-donor substituents (such as ether —O— or thio —S—), these polymers tend towards decomposition reactions in the sulfonic acid group at higher temperatures. Furthermore, ether bridges in particular are not sufficiently resistant to oxidative attacks (such as peroxide radicals, Fenton's test).

Therefore, it could be advantageous to provide new hydrolytically and thermo-oxidatively stable polymers that may be used advantageously, particularly for membrane and fuel cell technologies, and can be produced in a cost-effective manner. One particular task associated with this is providing a new method for producing such polymers.

SUMMARY

We provide new sulfonated poly(arylenes) featuring the structural element —X—Ar(SO₃M)_(n)-Y—, wherein the aromatic ring carrying the sulfonic acid group is exclusively substituted by electron-acceptor bridge groups (strongly deactivating groups, e.g. sulfones —SO₂— or ketones —CO—) X and Y, and, if applicable, by additional non-electron-donor substituents, as well as their synthesis and use.

Compared to aromates substituted by electron-donor groups (activating groups, e.g. sulfide —S— or ether —O—) or electron-donor and electron-acceptor-substituted aromates, the hydrolytic stability of sulfonic acid should be notably increased in an electron-acceptor-substituted aromate that does not feature an electron-donor substituent. This follows from theoretical considerations on the mechanism of the hydrolysis of sulfonated aromates and the reverse reaction, electrophile aromatic sulfonation. This reaction is generally reversible; the speed-determining step is the formation of the σ-complex as an intermediate stage of the electrophile aromatic substitution. With increased temperature and high water activity, the sulfonic acid group is separated with relative ease from the aromate (reversal of sulfonation), which limits the applicability of sulfonated poly(arylenes) to lower temperatures. All substituents that destabilize the intermediate stage of the electrophile aromatic substitution (σ-complex), such as deactivating electron-acceptor substituents in ortho or para position to the sulfonic acid, impede the reverse reaction (hydrolysis) and thus stabilize the sulfonic acid group at the aromate. However, this also extremely aggravates, or renders virtually impossible, the electrophile sulfonation of electron-acceptor-substituted aromates without additional electron-donor substituents.

This problem could be solved using a method in which initially a sulfonated polymer is produced wherein the aromatic ring substituted with a sulfonic acid group still carries at least one electron-donor substituent. Only afterwards is the electron-donor substituent chemically transformed into an electron-acceptor substituent. This transformation can be effected, for example, by means of oxidation of a sulfide group —S— (electron-donor) into a sulfone group —SO₂— (electron-acceptor).

Electron-acceptor groups like the ones used herein are electron-attracting groups that, as substituents, reduce the electron density on an aromatic ring (also referred to as deactivating groups). Electron-attracting groups have an −M- and/or −I-effect.

The resonance effect (M-effect, mesomerism effect) generally only works if the group is bound directly to an unsaturated (e.g. aromatic) system. It acts through π-electrons, as opposed to the field effect (1-effect, inductive effect), which acts through space or solvency molecules or preferably through the σ-bonds of a system.

−M-Effekt (negative resonance effect): A group has an −M-effect if the electron density in this group is greater than expected and the electron density in the unsaturated system is less than expected. Some examples, without limitation, for bridge groups with an −M-effect are: —SO₂—, —SO₂O—, —CO—, —COO—, —CONH—, —CONR— and —POR—. According to the invention, such groups are preferred.

Electron-donor groups like the ones used herein are therefore groups that, as substituents, increase the electron density in an aromatic ring (also referred to as activating groups). Electron-donor groups have a +M- and/or +I-effect. Examples for such bridge groups are ether —O— and sulfides (thioether) —S—.

The poly(arylenes) sulfonated according to the invention contain one or several structural elements of the formula —[—X—Ar(SO₃M)_(n)-Y—]—, wherein X and Y, which are identical or different from each other, each mean one electron-acceptor group, Ar represents an aromatic or heteroaromatic ring system with preferably 5-18 ring atoms, M represents a monovalent cation, and n means an integral number between 1 and 4, and wherein X, Y, Ar, M and n can be identical or different in various structural elements, independently of each other.

The bridge groups X and Y can be present at an aromatic ring in the para, meta and ortho position, the para position being generally preferred. Suitable examples, without limitation, for the electron-acceptor bridge groups X and Y are —SO₂—, —SO—, —SO₂O—, —CO—, —COO—, —CONH—, —CONR— and —POR—, wherein —SO₂— and —CO— are preferred and —SO₂— is especially preferred.

Specific examples, without limitation, for suitable aromatic or heteroaromatic ring systems are phenylene, naphthylene, anthracene, phenanthrene, biphenylene, furan, thiophene, pyrrole, thiazole, triazole, pyridine, imidazole and benzimidazole.

The aromatic or heteroaromatic ring can be substituted with one to four sulfonic acid groupings —SO₃M, i.e. in the above formulas, n=1-4, and for Ar=phenylene, n is preferably 1 or 2. The counterion M of the sulfonate group is either a proton, i.e. sulfonic acid is present, or a conventional monovalent cation. Typical examples of such a cation are metal ions such as Li⁺, Na⁺, K⁺ and NR₄ ⁺, PR₄ ⁺, wherein R represents an organic residue, preferably alkyl.

Apart from the sulfonic acid group and the bridge substituents X and Y, the aromatic or heteroaromatic rings can also contain additional non-electron-donor substituents. Some specific examples, without limitation, for such substituents are halogen, e.g. F, Cl, Br, or unsubstituted or substituted alkyl groups, e.g. —CH₃ or —CF₃.

In a preferred embodiment, Ar is phenylene, and the sulfonated poly(arylene) contains one or several of the following structural elements I, II or III

wherein X and Y, as defined above, are identical or different.

In a typical embodiment, the structural element(s) of the general formula —X—Ar(SO₃M)_(n)-Y— is/are formed by recurring elements of the formulas —[—Ar₁(SO₃M)_(n)-X—]— or —[—Ar₂(SO₃M)_(n)-Y—]—, wherein X and Y, which are identical or varying, mean one electron-acceptor group each, Ar₁ and Ar₂, which are identical or different from each other, represent an aromatic or heteroaromatic ring system Ar with preferably 5-18 ring atoms, as defined above; M represents a monovalent cation, as defined above; and n means an integral number between 1 and 4; and wherein X, Y, Ar₁, Ar₂, M and n can be identical or different in various structural elements, independently of each other; and the sulfonated aromatic or heteroaromatic ring systems Ar₁(SO₃M)_(n) or Ar₂(SO₃M)_(n) are not substituted by electron-donor groups. The elements —[—Ar₁(SO₃M)_(n)-X—]— and —[—Ar₂(SO₃M)_(n)-Y—]— can be identical or different in the type of the aromatic ring and/or in the degree of substitution and/or in the substitution positions.

In a specific embodiment of the present invention, the sulfonated poly(arylene) contains exclusively recurring elements of the formulas —[—Ar₁(SO₃M)_(n)-X—]— or —[—Ar₂(SO₃M)_(n)-Y—]—. Even more specifically, the sulfonated poly(arylene) contains exclusively one or more of the above structural elements I, II or III.

Especially preferred sulfonated poly(arylenes) are sulfonated poly(arylene sulfones), in particular poly(sulfonic acid phenylene sulfones), and their copolymers. Other examples, without limitation, for sulfonated poly(arylenes) according to the invention are poly(sulfonic acid phenylene ether ketones), poly(sulfonic acid phenylene sulfone ketones) and their copolymers.

However, the present invention also encompasses such copolymer poly(arylenes) which, in addition to the elements forming the structural element(s) of the general formula —X—Ar(SO₃M)_(n)-Y—, contain one or more elements of the formula —[—Ar₃—Z—]—, wherein Z can be an electron-donor group or an electron-acceptor group or neither, Ar₃ represents an aromatic or heteroaromatic ring system with preferably 5-18 ring atoms without SO₃M substituents, and the groups Ar₃ and Z can be identical or different in various elements —[—Ar₃—Z—]—, provided that the Z group can only be bound to a sulfonated aromatic or heteroaromatic ring system of the formula Ar(SO₃M)_(n) if Z does not represent an electron-donor.

Some suitable examples, without limitation, for the bridge group Z are —SO₂—, —SO—, SO₂O—, —CO—, —COO—, —CONH—, —CONR—, —POR—, —S—, —O— and alkylene. Other suitable groups are not difficult to discern for a polymer chemistry expert.

Specific examples, without limitation, for suitable aromatic or heteroaromatic Ar₃ ring systems are phenylene, naphthylene, anthracene, phenanthrene, biphenylene, furan, thiophene, pyrrole, thiazole, triazole, pyridine, imidazole, benzimidazole, etc. These ring systems may contain additional substituents in addition to the bridge substituents, if desired.

Another subject of the present invention are copolymers that, in addition to recurring elements of a sulfonated poly(arylene), as described above, also contain (preferably recurring) elements of at least one additional monomer or macromonomer.

Basically, any compound that can be copolymerized with the aryl monomers used according to the invention is suitable as an additional monomer or macromonomer. Typically, this will be a α,ω)-dihydroxy compound or a α,ω-dihalogen compound. Preferably, the α,ω-dihydroxy compound will feature the formula HO—W—OH, and the α,ω-dihalogen compound the formula Hal-W-Hal, wherein W is selected from the group consisting of —(CH₂)_(n)—, —(CF₂)_(n)—, —(CF₂CH₂)_(n)—, —(CH₂—CH₂—O)_(n)—CH₂—CH₂—, —(CH(CH₃)—CH₂—O)_(n)—CH(CH₃)—CH₂—, —(CF₂—CF₂—O)_(n)—CF₂—CF₂—, polyarylene ether sulfones, polyarylene ether ketones, polysiloxanes (e.g. —(SiR₂—O)_(n)—). Hal in the dihalogen compound represents a halogen residue, e.g. F, Cl, Br and I.

The pure, sulfonated poly(arylenes) or copolymers according to the invention can also be mixed with one or more conventional polymers in a known manner in order to obtain a polymer mixture that combines the advantageous characteristics of its individual components. For example, the polymers according to the inventions can be mixed on the basis of a sulfonated poly(arylene) with “softener components” in order to provide the resulting mixed polymer with greater flexibility and/or formability. Suitable polymers are known to the expert and can be selected, for example, from the group of PBI (polybenzimidazole), PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PSU (polysulfones), PES (polyether sulfones), PEK (polyether ketones), PPO (polyphenylene oxides), PPS (polyphenylene sulfides), PI (polyimides), PC (polycarbonates), PMMA (polymethyl methacrylates), polyphosphazenes.

In a specific embodiment, the pure, sulfonated poly(arylenes) or copolymers or polymer compounds of the invention can be integrated into an inert porous matrix, such as an organic (porous PE, PP, PVDF, PTFE, etc.) or anorganic matrix (porous boronitride, silicon dioxide, etc.).

In another embodiment, the pure, sulfonated poly(arylenes) or copolymers or polymer compounds of the invention can be reinforced with fiber materials, such as glass fibers, ceramic fibers, textile fibers, carbon fibers, microporous polypropylene or polytetrafluoroethylene, etc.

Furthermore, the pure, sulfonated poly(arylenes) or copolymers or the above polymer compounds of the invention can be combined with active or inactive fillers, including, but not limited to, TiO₂, ZrO₂ or SiO₂ particles, zirconium phosphates and phosphonates, tungstic or molybdic acid, etc., to form the corresponding composite materials. A combination with other conventional additives is also easily possible.

The sulfonated poly(arylenes) of the invention have molecular weights in the range of 2,000 to 2,000,000, typically in the range of 2,000 to 1,000,000, more frequently in the range of 10,000 to 1,000,000, preferably in the range of 2,000 to 200,000, especially preferably in the range of 10,000 to 100,000.

The synthesis of the sulfonated poly(arylenes) of the invention takes place by means of a multi-stage reaction: First, a sulfonated polymer is produced, which carries at least one electron-donor substituent at the sulfonated aromatic ring, which is subsequently transformed into an electron-acceptor substituent.

In a specific embodiment, the first step involves an already existing electron-donor-substituted polyarylene, produced by means of a conventional method or commercially available, being sulfonated by means of a known method, for example by reacting with SO₃ and/or H₂SO₄ (see example 11).

More frequently, however, the production of the sulfonated polymer involves a polycondensation of already sulfonated monomers. In this way, the composition and properties of the resulting sulfonated polyarylene can be adjusted as desired.

In general, such a production method involves the following steps:

a) Production of a sulfonated aryl monomer, F₁-AS-F₂, where AS represents an aryl system comprised of one or more aromatic rings, at least one of which is substituted with a sulfonic acid group, and the said aryl system features functional groups F₁ and F₂, which may be identical or different from each other and can enter into a condensation reaction, or several various aryl monomers of this kind; b) Polycondensation of the sulfonated aryl monomer or the sulfonated aryl monomers of step a) during the formation of a sulfonated poly(arylene) featuring at least one electron-donor substituent at the sulfonated aromatic rings; c) Transformation of the (at least) one electron-donor substituent into an electron-acceptor substituent during the formation of a sulfonated poly(arylene) featuring exclusively electron-acceptor substituents at the sulfonated aromatic rings.

In one variant of this method, the polycondensation, in addition to one or more sulfonated aryl monomers F₁-AS-F₂, as defined above, also involves one or more aryl monomers F₁-ANS-F₂, ANS representing an aryl system comprised of one or more aromatic rings not substituted with a sulfonic acid group, and the said aryl system featuring functional groups F₁ and F₂, as defined above, which may be identical or different from each other. This involves the formation of a partially sulfonated poly(arylene) featuring at least one electron-donor substituent at the sulfonated aromatic rings, and the said electron-donor substituent is subsequently transformed into an electron-acceptor substituent; in the course of this, a partially sulfonated poly(arylene) is formed which features exclusively electron-acceptor substituents at the sulfonated aromatic rings.

In a more specific embodiment, the production of a sulfonated poly(arylene sulfone) involves the following steps:

a) Production of a sulfonated aryl monomer, F₁-AS-F₂ featuring functional groups F₁ and F₂ which may be identical or different from each other and can react with a sulfide group in a condensation reaction, or several such aryl monomers, as defined above;

b) Polycondensation of the sulfonated aryl monomer or the sulfonated aryl monomers of step a) with an aryl disulfide or alkali sulfide during the formation of a sulfonated poly(arylene sulfide sulfone);

c) Oxidation of the sulfonated poly(arylene sulfide sulfone) of step b) into a sulfonated poly(arylene sulfone).

The functional groups F₁ and F₂ of the aryl monomers, identical or different, are preferably selected from the group consisting of fluorine, chlorine, bromine or iodine.

In one embodiment of the method according to the invention, the sulfonated aryl monomers follow the structural formula F₁—Ar₁-SO₂—Ar₂-F₂, i.e. AS=Ar₁—SO₂—Ar₂—, where Ar₁ and Ar₂ can be identical or different and each represents an aromatic or heteroaromatic ring system with 5-18 ring atoms, provided that Ar₁ and/or Ar₂ is/are substituted by at least one SO₃M group in at least one of the aryl monomers used, M being defined as described above.

The following Reaction Scheme I shows the basic steps of the method according to the invention based on the concrete, non-limiting example of the production of the homopolymer poly(sulfonic acid-1,4-phenylene sulfone) (detailed description in examples 1 and 2).

As already discussed above, only one aryl monomer can be used for this method, leading to the formation of a homopolymer poly(arylene sulfone), or two or more various aryl (co)monomers can be produced and subjected to a co-polycondensation and subsequent oxidation. In a specific embodiment of this method, the Ar₁ and/or Ar₂ residues are substituted by at least one SO₃M group in at least one of the aryl (co)monomers, M being defined as described above, and the Ar₁ and/or Ar₂ residues are not substituted with an SO₃M group in at least one other aryl monomer.

The functional groups F₁ and F₂ of the aryl monomers, identical or different, are preferably selected from the group consisting of fluorine, chlorine, bromine or iodine.

The following Reaction Scheme II shows the basic steps of the production of a copolymer sulfonated poly(arylene sulfone), using the initial monomers disodium-3,3′-disulfonate-4,4′-difluorodiphenylsulfone and 4,4′-difluorodiphenyl-sulfone (example 3). By specifying the ratio between the two initial monomers, the composition of the resulting polymer can be adjusted. In the above-mentioned Reaction Scheme II and the diagrams relating to examples 3-10, the reaction product of the polycondensation is represented as a block copolymer of the two different initial monomers, for better clarity. However, the present invention also encompasses, equally or even preferably, the corresponding statistic copolymers, which can be produced by the method described in example 3. Other statistic or block copolymers according to the invention can be produced in an analogous manner without much difficulty (see examples 4-10).

Preferred solvents for the polymerization reaction or copolymerization reaction are aprotic, polar, high-boiling solvents, such as 1-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethyl acetamide (DMAc), sulfolane, diphenyl sulfone, 1,3-dimethyl-2-imidazolidinone.

The reaction temperature is typically 100-250° C., preferably 140-200° C.

The reaction with alkali sulfide (e.g. sodium sulfide) generally takes place in the presence of additives such as alkali metal carboxylates (e.g. sodium acetate, lithium acetate), alkali metal carbonates (e.g. lithium carbonate), alkali metal sulfonates, lithium borate, lithium chloride.

The alkali sulfide (e.g. sodium sulfide) can also be used as a hydrate (e.g. Na₂S.9H₂O).

Such copolymers of different composition also feature different ion exchange capacities. The method described above offers the possibility of systematically producing copolymers with adjustable, variable ion exchange capacities (IEC=ion exchange capacity [mequiv/g], EW=equivalent weight [g/equiv]) by controlling the reaction process accordingly, using certain initial monomers and certain monomer ratios.

For the copolymer examples produced according to or analogous to the above scheme, the calculation formulas are indicated in the corresponding examples. For other copolymers according to the invention, the corresponding formulas may be empirically determined without difficulty.

In any case, when using the new membrane materials, a significantly increased hydrolytic and thermo-oxidative stability can be expected.

The sulfonated poly(arylene sulfones) of the invention can be characterized by various methods, e.g. by means of elementary analysis, NMR, solubilities, GPC, MALDI-TOF, DSC, x-ray, IEC through titration, density, IR, swelling in water and methanol, water absorption isotherms, water diffusion and electro-osmotic flow tests, conductivity measurements, particularly under higher temperatures when wetted, water absorption and hydrolytic stability tests (TGA under 1 atm water vapor) and thermo-oxidative stability (TGA in an oxygen atmosphere, e.g. 80% N₂ and 20% O₂). Some results of more recent tests are shown in FIGS. 1-4. Represented in FIGS. 5-11 are additional results of tests performed to study the properties of the polymers of the invention in more detail and compare them to those of sulfonated poly(arylene ether sulfones) and sulfonated poly(arylene sulfide sulfones) known from literature.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows the proton conductivity above 100° C. of poly(sulfonic acid-1,4-phenylene sulfone) compared to that of Nafion 117, measured in a water atmosphere (p(H₂O)=10⁵ Pa).

FIG. 2A shows the water absorption of Nafion 117 in a water atmosphere (p(H₂O)=10⁵ Pa).

FIG. 2B shows the water absorption of poly(sulfonic acid-1,4-phenylene sulfone) in a water atmosphere (p(H₂O)=10⁵ Pa).

FIG. 3A shows the water absorption of sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,3-phenylene-sulfide) in a water atmosphere (p(H₂O)=10⁵ Pa).

FIG. 3B shows the water absorption of sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide) in a water atmosphere (p (H₂O)=10⁵ Pa).

FIG. 4 shows the increased thermo-oxidative stability of a sulfonated poly(arylene sulfone) (S-PS 220) compared to the corresponding sulfonated poly(arylene sulfide sulfone) through thermogravimetric measurements in an oxygen-containing atmosphere (20% O₂ and 80% N₂).

FIG. 5A shows the increased thermo-oxidative stability of a sulfonated poly(arylene sulfone) (sPS-430, n=0.8, example 4) compared to a sulfonated poly(arylene sulfide sulfone) (sPSS-312, n=1.0, example 4) through thermogravimetric measurements in an oxygen-containing atmosphere (20% O₂ and 80% N₂, heating rate 2 K/min). The purely thermal stability of sPS-430 in a nitrogen atmosphere is also shown.

FIG. 5B shows that, in an oxygen-containing atmosphere, sulfonated poly(arylene sulfide sulfones) do not undergo a spontaneous transformation (oxidation) of the sulfide groups —S— into sulfone groups —SO₂— during the formation of sulfonated poly(arylene sulfones).

FIG. 6A shows the temperature-dependent water absorption and water desorption of Nafion® 117 in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h).

FIG. 6B shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfone) (sPS-220, n=1.0, example 2) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Reversible weight changes due to water desorption and absorption during the heating and cooling phases indicate the high hydrolytic stability of the sulfonic acid group.

FIG. 6C shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfone) (sPS-360, n=1.0, example 4) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Reversible weight changes due to water desorption and absorption during the heating and cooling phases indicate the high hydrolytic stability of the sulfonic acid group.

FIG. 6D shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfone) (sPS-430, n=0.8, example 4) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Reversible weight changes due to water desorption and absorption during the heating and cooling phases indicate the high hydrolytic stability of the sulfonic acid group.

FIG. 6E shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfone) (sPS-336, n=1.0, example 6) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Reversible weight changes due to water desorption and absorption during the heating and cooling phases indicate the high hydrolytic stability of the sulfonic acid group.

FIG. 6F shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene-ether-ether-ketone) (sPEEK-500, IEC=2.0 mmol/g) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Irreversible weight changes indicate the hydrolytic decomposition of the sulfonic acid at the aromate.

FIG. 6G shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfide sulfone) (sPS-204, n=1.0, example 2) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Irreversible weight changes prove the hydrolytic decomposition of the sulfonic acid at the aromate.

FIG. 6H shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfide sulfone) (sPS-312, n=1.0, example 4) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Irreversible weight changes indicate the hydrolytic decomposition of the sulfonic acid at the aromate.

FIG. 6I shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfide sulfone) (sPS-258, n=1.0, example 5) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Irreversible weight changes indicate the hydrolytic decomposition of the sulfonic acid at the aromate.

FIG. 6J shows the temperature-dependent water absorption and water desorption of a sulfonated poly(arylene sulfide sulfone) (sPS-304, n=1.0, example 6) in a water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h). Irreversible weight changes indicate the hydrolytic decomposition of the sulfonic acid at the aromate.

FIG. 7 shows the ¹³C-NMR spectra of a sample of a sulfonated poly(arylene sulfide sulfone) (sPSS-304, n=1.0, example 6) before and after the TGA in a water atmosphere (p(H₂O)=10⁵ Pa). The spectra indicate the quantitative separation of the sulfonic acid group of the aromate.

FIG. 8 shows the temperature-dependent water absorption from liquid water of a sulfonated poly(arylene sulfone) (sPS-430, n=0.8, example 4) compared to Nafion® 117, a sulfonated poly(arylene-ether-ether-ketone) (sPEEK, IEC=1.35 mmol/g) and a sulfonated poly(arylene sulfide sulfone) known from literature (sPSS-661, n=0.4, IEC=1.51 mmol/g).

FIG. 9 shows the temperature- and swelling-dependent proton conductivity of a sulfonated poly(arylene sulfone) (sPS-430, n=0.8, example 4), measured by means of impedance spectroscopy.

FIG. 10 shows the temperature-dependent proton conductivity of two sulfonated poly(arylene sulfones) (sPS-220, n=1.0, example 2, and sPS-430, n=0.8, example 4) compared to Nafion® 117 and a sulfonated poly(arylene-ether-ether-ketone) sPEEK, measured in a water atmosphere (p(H₂O)=10⁵ Pa) by means of impedance spectroscopy.

FIG. 11 shows the temperature- and mole-fraction-dependent swelling of a sulfonated poly(arylene sulfone) (sPS-430, n=0.8, example 4) in water/methanol compounds compared to Nafion® 117.

DETAILED DESCRIPTION

In characterization tests, the results of which are shown in FIGS. 1-4, the conductivity in a water atmosphere (p(H₂O)=10⁵ Pa) was determined by means of impedance spectroscopy, the water absorption of the polymers in a water atmosphere (p(H₂O)=10⁵ Pa) by means of TGA (thermogravimetric analysis), and the thermo-oxidative stability by means of TGA in an oxygen-containing atmosphere.

Through cyclic measurements between T=105 and 180° C. in a water atmosphere (p(H₂O)=10⁵ Pa; heating and cooling rate 12° C./h), the hydrolytic stability of the sulfonic acid group at the aromate can be estimated. Reversible weight changes due to water desorption and absorption during the heating and cooling phases indicate a high stability of the sulfonic acid group in the tested temperature range, while an irreversible weight change indicates a hydrolytic decomposition of the aromatic sulfonic acid. Since hydrolysis produces sulfuric acid as a reaction product and the sulfuric acid is more strongly hygroscopic than the corresponding sulfonic acid, an increasing water absorption can be observed during decomposition. Sulfonated poly(arylene sulfones) (FIG. 2A) and Nafion (FIG. 2B) are stable under these conditions, while the corresponding sulfonated poly(arylene sulfide sulfones) show decomposition reactions (FIGS. 3A and 3B).

To demonstrate the notable difference between the sulfonated poly(arylene sulfones) sPS described by this invention and the sulfonated poly(arylene ether ketones) and sulfonated poly(arylene sulfide sulfones) sPSS [Ref.: 1-6] known from literature, several of these reference polymers were produced, their properties examined in detail and compared to those of the polymers of the invention.

Structural element in sulfonated poly(arylene sulfones) sPS according to the invention:

Structural elements in sulfonated poly(arylene ether sulfones) and sulfonated poly(arylene sulfide sulfones) sPSS:

Another common name for poly(arylene sulfide sulfones) is poly(arylene thioether sulfones).

Apart from the differences in molecular structure between sulfonated poly(arylene ether sulfones) and/or sulfonated poly(arylene sulfide sulfones) and the pure, sulfonated poly(arylene sulfones), one can observe substantial differences in the thermal, thermo-oxidative and hydrolytic stability, as well as the solubility, swelling capacity and the conductivity of these polymers, all of which facilitates a distinctive classification.

For a thermal or thermo-oxidative stability comparison, thermogravimetric analyses (TGA with 2 K/min) were performed on the sulfonated poly(arylene sulfones) and the reference polymers in a nitrogen or oxygen-containing atmosphere (20% O₂ and 80% N₂, or pure O₂ atmosphere). These measurements resulted in a significantly larger stability range for sulfonated poly(arylene sulfones) sPS as compared to poly(arylene sulfide sulfones) sPSS. As shown in FIG. 5A, the decomposition reaction (probably separation of sulfonic acid groups from the aromate) already starts below 250° C. for poly(arylene sulfide sulfones) sPSS, while this reaction only starts above 300° C. for sulfonated poly(arylene sulfones) sPS with comparable exchange capacities. FIG. 5A illustrates the TGA of a sulfonated poly(arylene sulfone) sPS-430 (example 4, n=0.8) and a sulfonated poly(arylene sulfide sulfone) sPSS-312 (example 4, n=0.8) in an oxygen-containing atmosphere. The purely thermal stability of sPS-430 (example 4, n=0.8) in a nitrogen atmosphere is comparable to the thermo-oxidative stability or slightly higher, as is also shown in FIG. 5A.

In particular, a comparison of measurements in an inert atmosphere (nitrogen) and in an oxygen-containing atmosphere on sulfonated poly(arylene sulfide sulfones) sPSS (see FIG. 5B) shows that a transformation (oxidation) of the sulfide group into a sulfone group —SO₂— during the formation of pure, sulfonated poly(arylene sulfones) does not take place in a nitrogen-containing atmosphere. In an inert atmosphere, as well as in an oxygen-containing atmosphere, the decomposition of sulfonated poly(arylene sulfide sulfones) takes place at the same temperature, i.e. no stabilization effect can be observed in an oxygen-containing atmosphere when compared to an inert atmosphere. Therefore, this is not to be expected in a fuel cell either.

Even more clearly apparent is the difference between the sulfonated poly(arylene sulfones) and the sulfonated poly(arylene sulfide sulfones) known from literature [1-6] in the hydrolytic stability of the sulfonic acid group at the aromate. Through cyclic measurements between T=110° C. and 180° C. in a full water atmosphere (p(H₂O)=10⁵ Pa, heating and cooling rate 12° C./h), the hydrolytic stability of the sulfonic acid group at the aromate could be proven. Reversible weight changes due to water desorption and absorption during the heating and cooling phases indicate a high hydrolytic stability of the sulfonic acid group in the tested temperature range, while an irreversible weight change indicates a hydrolytic decomposition of the aromatic sulfonic acid. Since hydrolysis produces sulfuric acid as a reaction product and the sulfuric acid is more strongly hygroscopic than the corresponding sulfonic acid at the aromate, an increasing water absorption can initially be observed; during further decomposition, a weight reduction may occur. Only PFSA polymers such as Nafion® 117 (FIG. 6A) and sulfonated poly(arylene sulfones) sPS (FIG. 6B, 6C, 6D, 6E) are stable under these conditions, while the corresponding sulfonated poly(arylene-ether-ether-ketones) sPEEK known from literature (FIG. 6F) and the sulfonated poly(arylene sulfide sulfones) sPSS (FIG. 6G, 6H, 6I, 6J) [1-6] clearly show decomposition reactions. Through ¹³C-NMR tests, it could even be shown that a quantitative separation of the sulfonic acid groups of sulfonated poly(arylene sulfide sulfones) takes place under these reaction conditions (see FIG. 7).

Another significant difference appears in the water solubility of the sulfonated polymers. Typically, there is a clear correlation between the water solubility or swelling capacity (=water absorption) and the exchange capacity of a sulfonated polymer. Generally, the water solubility or swelling capacity of a sulfonated polymer increases with increasing exchange capacity (=ion exchange capacity, IEC). However, a high exchange capacity generally also results in a high ion conductivity. The goal, therefore, is to obtain a polymer that has the highest possible exchange capacity while at the same time being water-insoluble or not swelling too strongly. A comparison between sulfonated poly(arylenes) shows that the water solubility of sulfonated poly(arylene sulfones) as compared with sulfonated poly(arylene sulfide sulfones), sulfonated poly(arylene ether sulfones), sulfonated poly(arylene ether ketones) and sulfonated poly(arylene sulfides) with comparable exchange capacities is significantly reduced. Thus, sulfonated poly(arylene ether ketones) and poly(arylene sulfide sulfones), with an IEC of more than approximately 1.8-2.0 mmol/g, are nearly completely water-soluble (see polymers sPSS-312 (n=1.0) and sPSS-370 (n=0.8) in example 4), and/or also show excessive swelling with lower IECs in the range between 1.3-1.7 mmol/g starting at a temperature of about 50-70° C. (see FIG. 8). These polymers are therefore virtually useless for a fuel cell application or other applications in case of a high IEC or high temperatures. By contrast, analog polysulfones are water-insoluble even with an IEC of 2.5 mmol/g and above. In addition, they exhibit a nearly constant swelling behavior in water with temperatures up to 120° C. with average exchange capacities (<2.5 mmol/g) and high molecular weights (see FIG. 8), approximately comparable to Nafion® 117, which makes them interesting for applications in a broad temperature range up to far above 100° C. A significant advantage of the sulfonated poly(arylene sulfones) is thus presented by their potentially high exchange capacity and the associated high proton conductivity with simultaneous water-insolubility and low swelling rate in water. High proton conductivities in liquid water (σ=130 mS/cm at 25° C.) could be measured for the polymer sPS-430 (example 4, n=0.8) by means of impedance spectroscopy; FIG. 9 also shows the temperature- and swelling-dependent conductivity data of sPS-430 (example 4, n=0.8). Conductivities at T>100° C. in a water atmosphere also show comparable to better results as compared with Nafion® 117 as a reference polymer (see FIG. 10), as well as clearly improved conductivities compared to sulfonated poly(arylene-ether-ether-ketones) sPEEK.

Another difference appears in the swelling and solubility of sulfonated poly(arylene sulfones) in water/methanol compounds. PFSA (=perfluoro sulfonic acid) membranes, such as Nafion® or sulfonated poly(arylene sulfide sulfones) swell very strongly in methanol solutions; sulfonated poly(arylene sulfide sulfones) even become methanol-soluble with higher exchange capacities (see sPSS-312 (n=1.0) and sPSS-370 (n=0.8) in example 4). By contrast, sulfonated poly(arylene sulfones) in methanol/water compounds show a significantly lower swelling even with high methanol concentrations and high temperatures (demonstrated on sPS-430 in example 4, n=0.8, see FIG. 11), which also makes them very interesting for direct methanol fuel cells (DMFC). Compared to a Nafion® 117 membrane, the methanol flow through the membrane is also reduced by approximately half (with identical thickness), measured with a diffusion cell at 60° C. (half cells: 1 M methanol solution−water).

In addition, other interesting characteristics, such as a high ion permselectivity, can also be expected, which opens an application of these polymers up for various electromembrane processes. Thus, sulfonated poly(arylene sulfones) can be used for electrodialysis, Donnan dialysis and electrolysis. The high chemical and hydrolytic stability also facilitates their use in water electrolysis. Due to the possibility of producing membranes with very high exchange capacities and therefore charge densities, other interesting fields of application can be expected. For example, membranes made of hydrolytically stable poly(arylene sulfones) are also suitable for the humidification and dehumidification of gases. This property is as important for anode and cathode gas humidification as for simple applications such as air conditioning, especially in low-energy households. Furthermore, highly charged cation exchange membranes are suitable for electromagnetic screening, particularly in the GHz range, especially for WLAN applications. In addition, transparent films of highly charged sulfonated poly(arylene sulfones) can be used in the electrostatic coating of screens, especially LCD displays, for example laptops.

It has also been shown that a synthesis of sulfonated poly(arylene sulfones) via already sulfonated monomers with subsequent oxidation is preferable to an oxidation of already sulfonated poly(arylene sulfides), which has also been described in this invention. The latter method results in materials that have significantly worse coat-forming properties. (see example 11).

A similar result can be observed in the oxidation of poly(p-phenylene sulfides) with H₂O₂ in concentrated sulfuric acid, as described in the patent by J. Studinka, R. Gabler, Polyarylene sulphonates from sulphonated polyarylene sulphide by two-stage oxidation in acid medium DE 1938806A1 (1970) [7]; this involves the formation of a material insoluble in all known solvents, as well as infusible, and therefore cannot be thermally processed. Even if one assumes a sulfonation of the aromate through the use of concentrated sulfuric acid during oxidation, any coat-forming properties are lost. Moreover, the possibility of achieving higher exchange capacities (>0.1 mmol/g) by this method can be virtually excluded. The production of sulfonated poly(arylene sulfones) through the polymerization of already sulfonated monomers with subsequent oxidation is preferred to the sulfonation of an already existing poly(arylene sulfide) with subsequent or simultaneous oxidation.

The following examples are to illustrate the present invention in more detail, without limiting it to these examples.

EXAMPLE 1 Production of a Bifunctional Sulfonated Aryl Monomer a) Disodium-3,3′-disulfonate-4,4′-dichlorodiphenylsulfone (DSDCS)

In a flask provided with a cooler, 4,4′-dichlorodiphenylsulfone (30 g, 0.104 mol, Aldrich) and oleum (60 mL, 60% SO₃ in H₂SO₄, Aldrich) were heated to 110° C. and agitated for 12 h. After cooling the reaction mixture to room temperature, it was poured into 1000 mL of ice water. Then, sodium chloride (350 g) was added to precipitate the product. The white precipitate was obtained through filtration and dissolved again in 800 mL of water. After neutralizing the solution with NaOH, the product was once again precipitated with sodium chloride (200 g), filtrated and purified by means of recrystallization from a water/isopropanol mixture (2:8). Finally, the white product was vacuum-dried at 50° C. for 24 h (2·10⁻³ mbar). The yield was 30.5 g (59%) of disodium-3,3′-disulfonate-4,4′-dichloro-diphenyl-sulfone-monohydrate. The water content was dependent on the drying conditions and was determined by means of ¹H-NMR and elementary analysis.

¹H-NMR (300 MHz, DMSO-d₆): δ=8.24 (d, 2H, CH, J=2.4 Hz), 7.77 (dd, 2H, CH, J=2.4, 8.3 Hz), 7.58 (d, 2H, CH, J=8.3 Hz), 3.24 (s, 2H, H₂O), ¹³C-NMR (75.5 MHz, DMSO-d₆): δ=141.6 (s), 138.3 (s), 138.0 (s), 133.5 (s), 131.6 (s), 128.3 (s).

b) Disodium-3,3′-disulfonate-4,4′-difluorodiphenylsulfone (DSDFS)

This compound was produced analog to disodium-3,3′-disulfonate-4,4′-dichlorodiphenylsulfone (DSDCS) as a monohydrate to trihydrate (depending on the drying conditions). ¹H-NMR (300 MHz, DMSO-d₆): δ=8.06 (dd, 2H, CH, J_(HH)=2.5 Hz, J_(HF)=6.4 Hz), 7.87 (ddd, 2H, CH, J_(HH)=2.6, 8.7 Hz, J_(HF)=4.3 Hz), 7.32 (dd, 2H, CH, J_(HH)=8.8 Hz, J_(HF)=9.2 Hz), 3.23 (s, 2H, H₂O); ¹³C NMR (75.5 MHz, DMSO-d₆): δ=162.1 (d, J_(CF)=259.2 Hz), 137.4 (d, J_(CF)=18.9 Hz), 136.7 (d, J_(CF)=2.0 Hz), 131.5 (d, J_(CF)=10.0 Hz), 128.9 (d, J_(CF)=4.6 Hz), 119.0 (d, J_(CF)=24.6 Hz).

Instead of the sodium salt of the sulfonated monomers, the corresponding potassium salt was also produced and used for polymerizations.

EXAMPLE 2 Production of poly(sulfonic acid 1,4-phenylene sulfone)

I. Polymerization:

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 3.8591 g (7.578 mmol) of disodium-3,3′-disulfonate-4,4′-dichloro-diphenyl-sulfone-monohydrate (M=509.25 g/mol), 0.5914 g (7.578 mmol) of sodium sulfide (Na₂S) and 0.6216 g (7.578 mmol) of dried sodium acetate were filled into this flask. This mixture was vacuum-dried for 2 h at 100° C. (2·10⁻³ mbar). Then, 20 ml of dried 1-methyl-2-pyrrolidone (NMP) and 35 ml of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 4 h until it had reached 145° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (distilled) and the reaction was continued for 18 h at 190° C. After cooling it to room temperature, the black suspension was slowly dripped into isopropanol (800 mL) to precipitate the polymer. The gray precipitate was filtrated and rinsed with isopropanol. The product was then dissolved again in 50 mL of water (black solution), once again precipitated in isopropanol (800 mL), filtrated and rinsed with isopropanol and vacuum-dried (2·10⁻³ mbar). To remove all byproducts, the polymer was purified using 24-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a dark brown solid (4.346 g, M=452.39 g/mol Na⁺-form=9.62 mmol; M=596.51 g/mol Na⁺-form and 4H₂O/SO₃H=7.286 mmol, M=408.43 g/mol H⁺-form) was obtained. A portion of the sodium salt (approx. 0.2 g) was transformed by means of an ion exchanger (Dowex® Marathon® C) into the H⁺-form.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone, ethyl acetate, trifluoroacetic acid.

Exchange capacity: experimental: 4.890 mmol/g (204.50 g/mol) for H⁺-form theoretical: 4.500 mmol/g (222.24 g/mol) assumption: 1.0 H₂O/SO₃H theoretical: 4.897 mmol/g (204.22 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.6601 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.20 (d, 2H, CH, J_(HH)=1.7 Hz), 7.70 (dd, 2H, CH, J_(HH)=1.9, 8.0 Hz), 7.18 (d, 2H, CH, J_(HH)=8.3 Hz), 3.24 (s, 20H, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=148.6 (s), 141.6 (s), 139.0 (s), 135.0 (s), 129.1 (s), 127.1 (s).

Molecular Weight:

M_(n)=1672, M_(w)=2767 g/mol, D=1.6551 (batch 41, GPC)

M_(n)=46832, M_(w)=81145 g/mol, D=1.7327 (batch 19, GPC)

II. Oxidation:

Sulfonated poly(1,4-phenylene-sulfone): 4.34 g (9.62 mmol) of poly(sodium-sulfonate-phenylene-thio-sulfone) were dissolved in 50 mL of concentrated sulfuric acid, yielding a dark brown solution. Hydrogen peroxide (4.5 ml of 36% H₂O₂ in water, approx. 45 mmol H₂O₂) was slowly added. Then the reaction mixture was agitated for 2 days at room temperature. After diluting the mixture with 200 mL of water, the sulfuric acid was removed by means of dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=3000). The water was removed using a rotary evaporator and the product vacuum-dried at 50° C. (2·10⁻³ mbar). The yield was 2.3 g (5.22 mmol, M=440.42 g/mol) of a slightly brown-colored polymer.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc);

insoluble in aqueous 1M-NaCl solution, methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone, ethyl acetate, trifluoroacetic acid.

Exchange capacity: experimental: 4.270 mmol/g (234.19 g/mol) for H⁺-form theoretical: 4.198 mmol/g (238.22 g/mol) assumption: 1.0 H₂O/SO₃H theoretical: 4.541 mmol/g (220.21 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.745 g/cm³ for H⁺-form Analysis: experimental: C: 24.25, H: 3.84, S: 20.85, Cl: 0.70 theoretical: C: 32.72, H: 1.83, S: 29.11, Cl: 0.00 with 0.0 H₂O/SO₃H theoretical: C: 23.91, H: 4.35, S: 21.28, Cl: 0.00 with 4.5 H₂O/SO₃H theoretical: C: 23.73, H: 4.32, S: 21.11, Cl: 0.78 with 4.5 H₂O/SO₃H and polymerization rate = 30, Cl end groups

¹H-NMR (300 MHz, DMSO-d₆) δ=8.32 (s, 2H, CH), 8.19 (d, 2H, CH, J_(HH)=8.2 Hz), 7.99 (d, 2H, CH, J_(HH)=8.4 Hz), between 6 and 4 ppm (br s, SO₃H×n H₂O, depending on water content).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=147.7 (s), 144.0 (s), 143.3 (s), 133.1 (s), 128.9 (s), 128.5 (s).

EXAMPLE 3 Synthesis of a poly(sulfonic acid phenylene sulfone) with Variable Exchange Capacity Sulfonated poly(1,4-phenylene-sulfone) with n=0.7 and 0.8

${{EW}\left( {{sPS}\text{-}I} \right)} = \frac{{440.42\mspace{14mu} n}\; + \;{280.31\left( {1 - n} \right)}}{2\mspace{14mu} n}$ ${{EW}\left( {{sPSS}\text{-}I} \right)} = \frac{{408.43\mspace{14mu} n}\; + \;{248.31\left( {1 - n} \right)}}{2\mspace{14mu} n}$ N 1.0 0.9 0.8 0.7 0.6 0.5 IEC(sPS-I) 4.5411 4.2412 3.9177 3.5679 3.1883 2.7750 EW(sPS-I) 220.21 235.78 255.25 280.28 313.65 360.37 MW(sPS-I) 440.42 424.41 408.40 392.39 376.38 360.37 IEC(sPSS-I) 4.8968 4.5869 4.2507 3.8846 3.4845 3.0453 EW(sPSS-I) 204.22 218.01 235.25 257.42 286.99 328.37 MW(sPSS-I) 408.43 392.42 376.41 360.39 344.38 328.37 MW(sPSS-I-Na) 452.39 431.98 411.57 391.17 370.76 350.35 I. Polymerization (n=0.7):

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 3.8233 g (8.026 mmol, M=476.34 g/mol) of disodium-3,3′-disulfonate-4,4′-difluorodiphenylsulfone-monohydrate, 0.9299 g (3.657 mmol, M=254.25 g/mol) of 4,4′-difluorodiphenylsulfone, 0.8948 g (11.466 mmol) of sodium sulfide (Na₂S) and 0.958 g (11.466 mmol) of dried sodium acetate were filled into this flask. This mixture was vacuum-dried for 2 h at 70° C. (2·10⁻³ mbar). Then, 20 ml of dried 1-methyl-2-pyrrolidone (NMP) and 40 ml of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 2 h until it had reached 140° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (distilled) and the reaction was continued for 19 h at 180° C. After cooling it to room temperature, the dark purple suspension was slowly dripped into isopropanol (600 mL) to precipitate the polymer. The gray precipitate was filtrated and rinsed with isopropanol. The product was then dissolved again in 50 mL of water (dark brown solution), once again precipitated in isopropanol (800 mL), filtrated and rinsed with isopropanol and vacuum-dried (2·10⁻³ mbar). To remove all byproducts, the polymer was purified using 24-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=3000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a dark brown solid (3.80 g, M=391.17 g/mol Na⁺-form=9.71 mmol) was obtained.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid; insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

¹H-NMR (300 MHz, DMSO-d₆) δ=8.21 (d, 2H, CH, J_(HH)=1.6 Hz), 7.83 (br d, 1.6H, CH, J_(HH)=6.7 Hz), 7.70 (d, 2H, CH, J_(HH)=8.4 Hz), 7.45 (d, 1.6H, CH, J_(HH)=6.7 Hz), 7.17 (d, 2H, CH, J_(HH)=8.4 Hz), 3.25 (br s, 6H, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆) δ=148.6 (s), 141.6 (s), 141.3 (s), 140.5 (s), 139.0 (s), 135.0 (s), 132.1 (s), 129.4 (s), 129.0 (s), 127.1 (s).

Molecular weight: M_(n)=19612, M_(w)=27043 g/mol, D=1.3789 (GPC) for Na⁺-form

II. Oxidation (n=0.7):

Sulfonated poly(1,4-phenylene-sulfone): 2.188 g (approx. 5.59 mmol) of poly(sodium-sulfonate-phenylene-thio-sulfone) from the above reaction were dissolved in 50 mL of concentrated sulfuric acid, yielding a brown solution. Hydrogen peroxide (4.0 ml of 36% H₂O₂ in water, approx. 40 mmol H₂O₂) was slowly added. Then the reaction mixture was agitated for 2 days at room temperature. After diluting the mixture with 250 mL of water, the sulfuric acid was removed by means of dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=3000). The water was removed using a rotary evaporator and the product vacuum-dried at 50° C. (2·10⁻³ mbar). The yield was 1.93 g (M=392.39 g/mol H⁺-form=4.92 mmol) of a slightly yellowish polymer.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc);

insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 3.260 mmol/g (306.75 g/mol) for H⁺-form theoretical: 3.161 mmol/g (316.31 g/mol) assumption: 2.0 H₂O/SO₃H theoretical: 3.568 mmol/g (280.27 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.6835 g/cm³ for H⁺-form Analysis: experimental: C: 29.92, H: 3.41, S: 22.80 for H⁺- form theoretical: C: 36.73, H: 2.05, S: 27.77 with 0.0 H₂O/SO₃H theoretical: C: 29.21, H: 3.92, S: 22.09 with 4.0 H₂O/SO₃H

¹H-NMR (300 MHz, DMSO-d₆): δ=8.29 (br s and br d, together 4H, CH), 8.08 (m, 0.6H, CH), 7.97 (d, 2H, CH, J_(HH)=8.4 Hz), 7.85 (m, 0.6H, CH), 6.35 (br s, 12H, SO₃H×n H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=147.9 (s), 144.1 (s), 143.2 (s), 133.5 (s), 130.2 (weak s), 129.8 (weak s), 128.7 (s), 128.0 (s).

Molecular weight: M_(n)=33362, M_(w)=61256 g/mol, D=1.8361 (GPC) for H⁺-form

I. Polymerization (n=0.8):

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 3.6073 g (7.040 mmol) of disodium-3,3′-disulfonate-4,4′-difluoro-diphenyl-sulfone-trihydrate, 0.4475 g (1.760 mmol) of 4,4′-difluorodiphenylsulfone, 0.6868 g (8.801 mmol) of sodium sulfide (Na₂S) and 0.7938 g (9.680 mmol) of dried sodium acetate were filled into this flask. This mixture was vacuum-dried for 2 h at 70° C. (2·10⁻³ mbar). Then, 18 ml of dried 1-methyl-2-pyrrolidone (NMP) and 40 ml of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 12 h until it had reached 145° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (distilled) and the reaction was continued for 24 h at 175° C. After cooling it to room temperature, the black suspension was slowly dripped into isopropanol (600 mL) to precipitate the polymer. The gray precipitate was filtered out and rinsed with isopropanol. The product was then dissolved again in 50 mL of water (black solution), once again precipitated in isopropanol (800 mL), filtered out and rinsed with isopropanol and vacuum-dried (2·10⁻³ mbar). To remove all byproducts, the polymer was purified using 12-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a dark brown solid (2.69 g, M=411.57 g/mol Na⁺-form=6.54 mmol) was obtained.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

¹H-NMR (300 MHz, DMSO-d₆): δ=8.23 (s, 2H, CH), 7.83 (s, 1H, CH), 7.71 (d, 2H, CH), 7.45 (s, 1H, CH), 7.17 (d, 2H, CH), 3.33 (br s, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=148.6 (s), 141.6 (s), 141.0 (s), 140.4 (s), 139.0 (s), 135.0 (s), 132.1 (s), 129.4 (s), 129.1 (s), 127.1 (s).

II. Oxidation (n=0.8):

Sulfonated poly(1,4-phenylene-sulfone): 2.26 g (approx. 5.49 mmol) of poly(sodium-sulfonate-phenylene-thio-sulfone) from the above reaction were suspended in 30 mL of pure acetic acid, and then 10 mL of concentrated sulfuric acid added. Hydrogen peroxide (2.5 ml of 36% H₂O₂ in water, approx. 25 mmol H₂O₂) was slowly added. Then, the reaction mixture was agitated for 24 h at 55° C. After diluting the mixture with 200 mL of pure acetic acid, the colorless, slightly yellowish precipitate was filtered out. The product was cleaned by means of dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000) and vacuum-dried at 50° C. (2·10⁻³ mbar). The yield was 1.80 g (M=408.40 g/mol Na⁺-form=4.41 mmol) of a slightly yellowish polymer.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc);

insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 2.640 mmol/g (378.79 g/mol) for H⁺-form theoretical: 2.752 mmol/g (363.34 g/mol) assumption: 6.0 H₂O/SO₃H theoretical: 3.918 mmol/g (255.25 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.707 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.31 (br s, 2H, CH), 8.19 (br s, 2H, CH), 8.08 (br s, 0.4H, CH), 7.98 (br s, 2H, CH), 7.88 (s, 0.4H, CH), 5.16 (br s, SO₃H×n H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=147.7 (s), 144.0 (s), 143.3 (s), 133.1 (s), 130.2 (weak s), 129.8 (weak s), 128.8 (s), 128.4 (s). Analog to the reactions described in EXAMPLE 3, additional copolymers with different exchange capacities were produced using various ratios of the initial monomers disodium-3,3′-disulfonate-4,4′-difluorodiphenylsulfone and 4,4′-difluorodiphenylsulfone, or disodium-3,3′-disulfonate-4,4′-dichlorodiphenylsulfone and 4,4′-dichlorodiphenylsulfone. The reaction conditions were analog.

EXAMPLE 4 Synthesis of a poly(sulfonic acid arylene sulfone) with Variable Exchange Capacity Sulfonated poly(1,4-phenylene-sulfone) with n=1.0 and n=0.8

Dithiol component: 4,4′-thiobisbenzolthiol (bis-(4-mercapto-phenyl)sulfide)

${{EW}\left( {s\text{-}{PS}\text{-}{III}} \right)} = \frac{{720.74\mspace{14mu} n}\; + \;{560.62\left( {1 - n} \right)}}{2\mspace{14mu} n}$ ${{EW}\left( {s\text{-}{PSS}\text{-}{III}} \right)} = \frac{{624.74\mspace{14mu} n}\; + \;{464.62\mspace{11mu}\left( {1 - n} \right)}}{2\mspace{14mu} n}$ N 1.0 0.9 0.8 0.7 0.6 0.5 IEC(sPS-III) 2.7749 2.5542 2.3232 2.0812 1.8273 1.5608 EW(sPS-III) 360.37 391.52 430.4475 480.50 547.24 640.68 MW(sPS-III) 720.74 704.73 688.72 672.70 656.69 640.68 IEC(sPSS-III) 3.2013 2.9570 2.6994 2.4276 2.1402 1.8359 EW(sPSS-III) 312.37 338.18 370.45 411.93 467.24 544.68 MW(sPSS-III) 624.74 608.73 592.72 576.70 560.69 544.68 MW(sPSS-III-Na) 668.70 648.29 627.88 607.48 587.07 566.66 1. Batch I. Polymerization:

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,4-phenylene-sulfide-1,4-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 3.276 g (6.394 mmol) of disodium-3,3′-disulfonate-4,4,-difluorodiphenylsulfone-trihydrate, 1.601 g (6.394 mmol) of 4,4′-thiobisbenzolthiol and 1.060 g (7.673 mmol) of dried potassium carbonate were filled into this flask. This mixture was vacuum-dried for 2 h at 70° C. (2·10⁻³ mbar). Then, 18 ml of dried 1-methyl-2-pyrrolidone (NMP) and 40 ml of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 4 h until it had reached 145° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (distilled) and the reaction was continued for 15 h at 185° C. After cooling it to room temperature, the black suspension was slowly dripped into isopropanol (600 mL) to precipitate the polymer. The gray precipitate was filtrated and rinsed with isopropanol. The product was then dissolved again in 100 mL of water (brown solution), once again precipitated in isopropanol (600 mL), filtrated and rinsed with isopropanol and vacuum-dried (2·10⁻³ mbar). To remove all byproducts, the polymer was purified using 24-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a dark brown solid (4.056 g, M=668.70 g/mol Na⁺-form=6.07 mmol) was obtained.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

¹H-NMR (300 MHz, DMSO-d₆): δ=8.09 (s, 2H, CH), 7.57 (d, 2H, CH, J_(HH)=8.3 Hz), 7.44 (d, 4H, CH, J_(HH)=7.9 Hz), 7.37 (d, 4H, CH, J_(HH)=7.9 Hz), 6.80 (d, 2H, CH, J_(HH)=8.3 Hz).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=144.7 (s), 144.1 (s), 136.5 (s), 136.2 (s), 135.9 (s), 132.0 (s), 130.8 (s), 127.6 (s), 126.0 (s).

Molecular weight: M_(n)=8378, M_(w)=34670 g/mol, D=4.1383 (GPC) for Na⁺-form

II. Oxidation:

Sulfonated poly(1,4-phenylene-sulfone): 3.22 g (4.82 mmol, M=668.70 g/mol) finely mortared solid from the above reaction were suspended in 50 mL of pure acetic acid and 10 mL of concentrated sulfuric acid. The dark brown reaction mixture was heated to 55° C., and then 8 mL of a 36% hydrogen peroxide solution (approx. 80 mmol H₂O₂) were slowly dripped in. This mixture was agitated for 5 h at 55° C., during which time the solid gradually lost its color. Subsequently, the mixture was briefly heated to 110° C. to remove any excess peroxide. Then the mixture was diluted with 150 mL of pure acetic acid. The pale yellow to colorless solid was filtered out and rinsed several times in pure acetic acid. To remove all byproducts, the polymer was purified using 48-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a pale yellow solid (2.83 g, M=720.74 g/mol=3.93 mmol) was obtained.

Solubility:

Soluble in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc);

insoluble in water (only swelling), methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 2.210 mmol/g (452.49 g/mol) for H⁺-form theoretical: 2.211 mmol/g (452.25 g/mol) assumption: 5.1 H₂O/SO₃H theoretical: 2.755 mmol/g (360.37 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.693 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.44 (br, 4H, CH), 8.16 (br, 2H, CH), 7.94 (br, 4H, CH), 7.89 (br, 4H, CH), 5.01 (br, 9H, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=150.0 (s), 146.9 (s), 144.7 (s), 144.1 (s), 141.2 (s), 134.2 (s), 129.9 (s), 128.6 (s)

2. Batch

I. Polymerization (n=1.0):

sPSS-312 (n=1.0) Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,4-phenylene-sulfide-1,4-phenylene-sulfide):

The polymerization was carried out in a heated 1000 mL flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 30.170 g (0.0658 mol) of disodium-3,3′-disulfonate-4,4′-difluoro-diphenyl-sulfone, 16.482 g (0.0658 mol) of 4,4′-thiobisbenzolthiol and 19.1 g (0.138 mol) of dried potassium carbonate were filled into this flask. Then, 200 mL of dried 1-methyl-2-pyrrolidone (NMP) and 80 mL of dried toluene were added and the reaction mixture agitated for 30 minutes at room temperature under low current argon. Finally, the reaction mixture was heated in an oil bath for 3 h until it had reached 150° C., in order to remove all traces of water (dehydrator). Afterwards, the toluene was removed (distilled) by draining the Dean-Stark trap and the reaction continued for 36 h at 185° C.; after 24 h, another 100 mL of NMP were added. After cooling it to room temperature, the dark purple suspension was slowly dripped into isopropanol (1200 mL) to precipitate the polymer. The purple precipitate was filtrated and rinsed with isopropanol. The product was then dissolved in 600 mL of water (dark purple solution) and once again precipitated in isopropanol (1200 mL), before the gray precipitate was filtrated and rinsed with isopropanol. To remove all byproducts, the polymer was purified using 36-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=12,000-14,000); after removing the solvent and vacuum-drying at 60° C., a dark purple solid (38.46 g, M=700.94 g/mol K⁺-form, 83.4%) was obtained. A portion (7.93 g) of the polymer was transformed by means of an ion exchanger (Dowex® Marathon® C) into the H⁺-form. The result was a light brown polymer (6.96 g, 98.5%), which was vacuum-dried for 12 h at 60° C. According to the ¹H-NMR spectrum, the polymer still contains 3.7H₂O/SO₃H, i.e. the measured ion exchange capacity (IEC), after deducting these 3.7H₂O/SO₃H (IEC=3.116 mmol/g), approximately matches the theoretically expected IEC of 3.201 mmol/g.

Solubility:

Soluble in water, methanol (H⁺-form), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid.

Insoluble in methanol (Na/K⁺-form), ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 2.580 mmol/g (387.60 g/mol) for H⁺-form theoretical: 2.638 mmol/g (379.03 g/mol) assumption: 3.7 H₂O/SO₃H theoretical: 3.201 mmol/g (312.37 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.560 g/cm³ for H⁺-form with 3.7 H₂O/SO₃H

¹H-NMR (300 MHz, DMSO-d₆): δ=8.09 (s, 2H, CH), 7.57 (d, 2H, CH, J_(HH)=8.3 Hz), 7.44 (d, 4H, CH, J_(HH)=7.9 Hz), 7.37 (d, 4H, CH, J_(HH)=7.9 Hz), 6.80 (d, 2H, CH, J_(HH)=8.3 Hz).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=144.7 (s), 144.1 (s), 136.5 (s), 136.2 (s), 135.9 (s), 132.0 (s), 130.8 (s), 127.6 (s), 126.0 (s).

Molecular weight: M_(n)=21229 g/mol, M_(w)=52025 g/mol, D=2.45 (GPC in DMF/60° C./salt additive/relative to polystyrol standard) for Na/K⁺-form

II. Oxidation (n=1.0):

sPS-360 (n=1.0) Sulfonated poly(1,4-phenylene-sulfone):

20.0 g (28.5 mmol, M=700.92 g/mol for potassium form) finely mortared purple solid from the above reaction (sPSS-312, n=1.0) were suspended in 400 mL of pure acetic acid and 15 mL of concentrated sulfuric acid. 26 mL of a hydrogen peroxide solution (30%, approx. 0.26 mol H₂O₂) were slowly dripped into the dark brown reaction mixture. This mixture was agitated for 36 h at room temperature, during which time the solid gradually lost its color. Then the mixture was diluted with 200 mL of pure acetic acid. The pale yellow to colorless solid was filtrated and rinsed several times in pure acetic acid. To remove all byproducts, the polymer was purified using 48-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=12,000-14,000); after removing the solvent and vacuum-drying at 60° C., a pale yellow solid (18.25 g, M=720.74 g/mol=88.9%) was obtained. Transparent films could be obtained from DMAc, DMSO and NMP solutions (20 wt %).

Solubility:

Soluble in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc); insoluble in water (only swelling), methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Conductivity at 25° C.: 128 mS/cm (in liquid water)

E-modulus at 30° C.: 600 MPa (DMA with 1 Hz, measured in air, previously swelled in water)

Relative viscosity: 2.972 at 25° C., c = 1 g/dL in DMSO Inherent viscosity: 1.089 dL/g at 25° C., c = 1 g/dL in DMSO Exchange capacity: experimental: 2.730 mmol/g (366.30 g/mol) for H⁺-form theoretical: 2.775 mmol/g (360.37 g/mol) assumption: 0.0 H₂O/SO₃H Density: g/cm³ for H⁺-form (no data)

¹H-NMR (300 MHz, DMSO-d₆): δ=8.44 (br, 4H, CH), 8.16 (br, 2H, CH), 7.94 (br, 4H, CH), 7.89 (br, 4H, CH), 5.01 (br, 9H, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=150.0 (s), 146.9 (s), 144.7 (s), 144.1 (s), 141.2 (s), 134.2 (s), 129.9 (s), 128.6 (s).

3. Batch

I. Polymerization (n=0.8):

sPSS-370 (n=0.8) Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,4-phenylene-sulfide-1,4-phenylene-sulfide):

The polymerization was carried out in a heated 1000 mL flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 30.090 g (65.65 mmol) of disodium-3,3′-disulfonate-4,4′-difluoro-diphenyl-sulfone, 4.173 g (16.40 mmol) of 4,4′-difluorodiphenylsulfone, 20.548 g (82.06 mmol) of 4,4′-thiobisbenzolthiol and 17.0 g (0.123 mol) of dried potassium carbonate were filled into this flask. Then, 200 mL of dried 1-methyl-2-pyrrolidone (NMP) and 80 mL of dried toluene were added and the reaction mixture agitated for 30 minutes at room temperature under current argon. Finally, the reaction mixture was heated in an oil bath for 3 h until it had reached 150° C., in order to remove all traces of water (dehydrator). Afterwards, the toluene was removed (distilled) by draining the Dean-Stark trap and the reaction continued for 36 h at 185° C.; after 24 h, another 100 mL of NMP were added. After cooling it to room temperature, the dark purple suspension was slowly dripped into isopropanol (1200 mL) to precipitate the polymer. The purple precipitate was filtrated and rinsed with isopropanol. The product was then dissolved in 600 mL of water (dark purple solution) and once again precipitated in isopropanol (1200 mL), before the gray precipitate was filtrated and rinsed with isopropanol. To remove all byproducts, the polymer was purified using 36-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=12,000-14,000); after removing the solvent and vacuum-drying at 60° C., a dark purple solid (33.07 g, M=653.66 g/mol K⁺-form, 61.7%) was obtained. A portion (7.47 g) of the polymer was transformed by means of an ion exchanger (Dowex® Marathon® C) into the H⁺-form. The result was a light brown solid (6.50 g, 96.0%), which was vacuum-dried for 12 h at 60° C.

Solubility:

Soluble in water, methanol (H⁺-form), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

Insoluble in methanol (Na/K⁺-form), ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 2.175 mmol/g (459.77 g/mol) for H⁺-form theoretical: 2.175 mmol/g (459.77 g/mol) assumption: 5.0 H₂O/SO₃H theoretical: 2.699 mmol/g (370.45 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.526 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.09, 7.70, 7.57, 7.44, 7.37, 7.20, 6.80.

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=144.7 (s), 144.4 (weak s), 144.2 (s), 138.5 (weak s), 136.5 (s), 136.2 (s), 135.9 (s), 135.6 (weak s), 132.0 (s), 130.8 (s), 130.2 (weak s), 128.4 (s), 127.6 (s), 126.0 (s).

Molecular weight: M_(n)=169680 g/mol, M_(w)=315424 g/mol, D=1.86 (GPC in DMF/60° C./salt additive/relative to polystyrol standard) for Na/K⁺-form

II. Oxidation (n=0.8):

sPS-430 (n=0.8) Sulfonated poly(1,4-phenylene-sulfone):

20.0 g (28.5 mmol, M=700.92 g/mol for potassium form) finely mortared purple solid from the above reaction (sPSS-370, n=0.8) were suspended in 400 mL of pure acetic acid and 15 mL of concentrated sulfuric acid. 26 mL of a hydrogen peroxide solution (30%, approx. 0.26 mol H₂O₂) were slowly dripped into the dark brown reaction mixture. This mixture was agitated for 36 h at room temperature, during which time the solid gradually lost its color. Then the mixture was diluted with 200 mL of pure acetic acid. The pale yellow to colorless solid was filtrated and rinsed several times in pure acetic acid. To remove all byproducts, the polymer was purified using 48-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=12,000-14,000); after removing the solvent and vacuum-drying at 60° C., a pale yellow solid (18.25 g, M=720.74 g/mol=88.9%) was obtained. Transparent films could be obtained from DMSO, DMAc, and NMP solutions (20 wt %).

Solubility:

Soluble (after heating) in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc);

insoluble in water (only swelling), methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Conductivity at 25° C.: 130 mS/cm (in liquid water)

E-modulus at 60° C.: 600 MPa (DMA with 1 Hz, measured in air, previously swelled in water)

Exchange capacity: experimental: 1.970 mmol/g (507.61 g/mol) for H⁺-form theoretical: 1.970 mmol/g (507.61 g/mol) assumption: 4.3 H₂O/SO₃H theoretical: 2.323 mmol/g (430.45 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.66 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.48 (d), 8.44 (s), 8.16 (d), 8.10 (s), 7.94 (d), 7.89 (d), 5.0 (H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=150.1 (s), 146.9 (s), 145.1 (weak s), 144.7 (s), 144.1 (s), 143.6 (weak s), 141.2 (s), 134.2 (s), 130.2 (s), 129.9 (s), 128.6 (s).

Molecular weight: M_(n)=44151, M_(w)=679752 g/mol, D=15.4 (GPC in DMF/60° C./salt additive/relative to polystyrol standard) for H⁺-form (low solubility in DMF).

EXAMPLE 5 Synthesis of a poly(sulfonic acid phenylene sulfone) with Variable Exchange Capacity Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,3-phenylene-sulfone) with n=1.0 and 0.8

Dithiol Component: benzene-1,3-dithiol

${{EW}\left( {{sPS}\text{-}{II}} \right)} = \frac{{580.58\mspace{14mu} n}\; + \;{420.46\left( {1 - n} \right)}}{2\mspace{14mu} n}$ ${{EW}\left( {{sPSS}\text{-}{II}} \right)} = \frac{{516.58\mspace{14mu} n}\; + \;{356.47\left( {1 - n} \right)}}{2\mspace{14mu} n}$ N 1.0 0.9 0.8 0.7 0.6 0.5 IEC(sPS-II) 3.4448 3.1883 2.9167 2.6289 2.3232 1.9979 EW(sPS-II) 290.29 313.65 342.85 380.39 430.44 500.52 MW(sPS-II) 580.58 564.57 548.56 532.54 516.53 500.52 IEC(sPSS-II) 3.8716 3.5959 3.3020 2.9880 2.6517 2.2908 EW(sPSS-II) 258.29 278.09 302.85 334.68 377.11 436.53 MW(sPSS-II) 516.58 500.57 484.56 468.55 452.54 436.53 MW(sPSS-II-Na) 560.54 540.13 519.73 499.32 478.91 458.51 I. Polymerization (n=1.0):

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,3-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 4.8537 g (9.531 mmol, M=509.25 g/mol) of disodium-3,3′-disulfonate-4,4′-dichlorodiphenylsulfone-monohydrate, 1.3557 g (9.531 mmol) of benzene-1,3-dithiol and 1.449 g (10.5 mmol) of dried potassium carbonate were filled into this flask. This mixture was vacuum-dried for 2 h at 70° C. (2·10⁻³ mbar). Then, 15 mL of dried 1-methyl-2-pyrrolidone (NMP) and 25 mL of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 4 h until it had reached 150° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (destilled) and the reaction was continued for 20 h at 190° C. After cooling it to room temperature, the slightly yellowish suspension was slowly dripped into isopropanol (500 mL) to precipitate the polymer. The slightly pink precipitate was filtrated and rinsed with isopropanol. The product was then dissolved again in 50 mL of water, once again precipitated in isopropanol (800 mL), filtrated, rinsed with isopropanol and vacuum-dried (2·10⁻³ mbar). To remove all byproducts, the polymer was purified using 24-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a pink-colored solid (5.10 g, M=560.54 g/mol Na⁺-form=9.10 mmol) was obtained. A portion of the sodium salt (approx. 1.0 g) was transformed by means of an ion exchanger (Dowex® Marathon® C) into the H⁺-form.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

insoluble in aqueous 1M-NaCl solution, methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone, ethyl acetate, trifluoroacetic acid.

Exchange experimental: 3.940 mmol/g (253.81 g/mol) capacity: for H⁺-form theoretical: 3.619 mmol/g (276.31 g/mol) assumption: 1.0 H₂O/SO₃H theoretical: 3.872 mmol/g (258.29 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.5778 g/cm³ for H⁺-form Analysis: experimental: C: 31.27, H: 4.28, S: 21.61, Cl: 0.67 theoretical: C: 41.85, H: 2.34, S: 31.03, Cl: 0.00 with 0.0 H₂O/SO₃H theoretical: C: 31.02, H: 4.63, S: 23.00, Cl: 0.00 with 5.0 H₂O/SO₃H theoretical: C: 30.87, H: 4.61, S: 22.89, Cl: 0.51 with 5.0 H₂O/SO₃H and polymerization rate = 20, Cl end groups

¹H-NMR (300 MHz, DMSO-d₆): δ=8.08 (d, 2H, CH, J_(HH)=1.7 Hz), 7.61 (s, 1H, CH), 7.56 (dd, 2H, CH, J_(HH)=1.7, 7.2 Hz), 7.48 (s, 3H, CH), 6.85 (d, 2H, CH, J_(HH)=7.2 Hz), 4.96 (s, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=145.4 (s), 144.5 (s), 141.3 (s), 137.3 (s), 136.7 (s), 134.2 (s), 132.7 (s), 128.6 (s), 128.5 (s), 126.8 (s).

II. Oxidation (n=1.0):

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,3-phenylene-sulfone): 3.08 g (5.49 mmol, M=560.54 g/mol) of solid from the above reaction were dissolved in 50 mL of concentrated sulfuric acid 5 mL of a 36% hydrogen peroxide solution (approx. 50 mmol H₂O₂) were slowly dripped into this slightly greenish solution, resulting in a color shift towards pale yellow. This mixture was agitated for 1 d at room temperature. After diluting the mixture with 200 mL of water, the sulfuric acid was removed by means of dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=3000). The water was removed using a rotary evaporator and the product vacuum-dried at 50° C. (2·10⁻³ mbar). The yield was 2.40 g (4.13 mmol, M=580.58 g/mol) of a pale yellow solid.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc);

insoluble in aqueous 1M-NaCl solution, methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone, ethyl acetate, trifluoroacetic acid.

Exchange capacity: experimental: 2.270 mmol/g (440.53 g/mol) for H⁺-form theoretical: 2.302 mmol/g (434.41 g/mol) assumption: 8.0 H₂O/SO₃H theoretical: 3.445 mmol/g (290.29 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.6503 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.45 und 8.44 (two s, together 4H, CH), 8.16 (d, 2H, CH, J_(HH)=7.2 Hz), 7.88 (d, 2H, CH, J_(HH)=7.2 Hz), 7.46 (t, 1H, CH, J_(HH)=6.5 Hz), 3.87 (s, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=149.6 (s), 144.4 (s), 142.4 (s), 141.9 (s), 134.2 (s), 133.4 (s), 130.1 (s), 129.9 (s), 129.8 (s), 128.4 (s).

I. Polymerization (n=0.8):

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,3-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 4.4466 g (9.335 mmol) of disodium-3,3′-disulfonate-4,4′-difluorodiphenylsulfone-monohydrate, 0.5933 g (2.334 mmol) of 4,4′-difluorodiphenylsulfone, 1.6596 g (11.668 mmol) of benzene-1,3-dithiol and 3.225 g (23.336 mmol) of dried potassium carbonate were filled into this flask. This mixture was vacuum-dried for 2 h at 90° C. (2·10⁻³ mbar). Then, 20 ml of dried 1-methyl-2-pyrrolidone (NMP) and 35 ml of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 4 h until it had reached 145° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (distilled) and the reaction was continued for 24 h at 180° C. After cooling it to room temperature, the dark purple suspension was slowly dripped into isopropanol (800 mL) to precipitate the polymer. The pink-colored precipitate was filtrated and rinsed with isopropanol. The product was then dissolved again in 50 mL of water (purple solution), once again precipitated in isopropanol (800 mL), filtrated, rinsed with isopropanol and vacuum-dried (2·10⁻³ mbar). To remove all byproducts, the polymer was purified using 24-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=3000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a purple solid (3.66 g, M=519.73 g/mol Na⁺-form=7.04 mmol) was obtained.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, methylene chloride, acetone.

¹H-NMR (300 MHz, DMSO-d₆) δ=8.10, 7.73, 7.62, 7.59, 7.51, 7.24, 6.78.

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=145.4, 145.1, 144.8, 144.6, 144.1, 141.3, 140.0, 139.1, 138.6, 137.3, 136.9, 136.7, 136.6, 135.3, 134.2, 133.3, 132.7, 128.9, 128.6, 128.5, 127.5, 126.7, 126.5.

II. Oxidation (n=0.8):

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,3-phenylene-sulfone): 3.066 g (5.90 mmol, M=519.73 g/mol) of solid from the above reaction were suspended in 50 mL of concentrated sulfuric acid 6 mL of a 36% hydrogen peroxide solution (approx. 60 mmol H₂O₂) were slowly dripped into this green solution, resulting in a color shift towards pale yellow. This mixture was agitated for 1 d at room temperature. After diluting the mixture with 200 mL of water, the sulfuric acid was removed by means of dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=3000). The water was removed using a rotary evaporator and the product vacuum-dried at 50° C. (2·10⁻³ mbar). The yield was 2.21 g (4.0 mmol, M=548.56 g/mol) of a pale yellow solid.

Solubility: virtually insoluble in all solvents in H₂O (swelling)

Exchange capacity: experimental: 2.680 mmol/g (373.13 g/mol) for H⁺-form theoretical: 2.624 mmol/g (381.10 g/mol) assumption: 4.5 H₂O/SO₃H theoretical: 2.677 mmol/g (373.55 g/mol) assumption: 4.0 H₂O/SO₃H theoretical: 2.919 mmol/g (342.58 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.648 g/cm³ for H⁺-form Analysis: experimental: C: 31.83, H: 3.12, S: 21.24 for H⁺- form theoretical: C: 39.41, H: 2.20, S: 26.88, with 0.0 H₂O/SO₃H theoretical: C: 31.87, H: 3.92, S: 21.74, with 4.5 H₂O/SO₃H

¹H-NMR (300 MHz, DMSO-d₆): δ=8.45 (br, CH), 8.08 (br, CH), 7.84 (br, CH), 6.19 (br, CH), 5.66 (br, CH), 4.04 (H₂O).

¹³C-NMR: unknown, due to very low solubility

Molecular weight: unknown, due to very low solubility

EXAMPLE 6 Synthesis of a poly(sulfonic acid phenylene sulfone) with Variable Exchange Capacity Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,4-phenylene-oxide) with n=1.0

Dithiol Component: 4,4′-oxobisbenzolthiol (bis-(4-mercapto-phenyl)oxide)

${{EW}\left( {{sPS}\text{-}{IV}} \right)} = \frac{{672.68\mspace{14mu} n}\; + \;{512.56\left( {1 - n} \right)}}{2\mspace{14mu} n}$ ${{EW}\left( {{sPSS}\text{-}{IV}} \right)} = \frac{{608.68\mspace{14mu} n}\; + \;{448.56\left( {1 - n} \right)}}{2\mspace{14mu} n}$ N 1.0 0.9 0.8 0.7 0.6 0.5 IEC(sPS-IV) 2.9732 2.7411 2.4974 2.2413 1.9716 1.6874 EW(sPS-IV) 336.34 364.82 400.41 446.17 507.19 592.62 MW(sPS-IV) 672.68 656.67 640.66 624.64 608.63 592.62 IEC(sPSS-IV) 3.2858 3.0371 2.7746 2.4971 2.2033 1.8917 EW(sPSS-IV) 304.34 329.26 360.41 400.46 453.86 528.62 MW(sPSS-IV) 608.68 592.67 576.66 560.64 544.63 528.62 MW(sPSS-IV-Na) 652.64 632.23 611.82 591.42 571.01 550.60 I. Polymerization:

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,4-phenylene-oxide-1,4-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 2.2566 g (4.404 mmol) of disodium-3,3′-disulfonate-4,4′-difluorodiphenylsulfone-trihydrate, 1.0320 g (4.404 mmol) of 4,4′-oxobisbenzolthiol and 0.852 g (6.16 mmol) of dried potassium carbonate were filled into this flask. This mixture was vacuum-dried for 2 h at 70° C. (2-10⁻³ mbar). Then, 18 ml of dried 1-methyl-2-pyrrolidone (NMP) and 40 ml of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 4 h until it had reached 145° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (distilled) and the reaction was continued for 15 h at 185° C. After cooling it to room temperature, the black suspension was slowly dripped into isopropanol (600 mL) to precipitate the polymer. The brown precipitate was filtrated and rinsed with isopropanol. The product was then dissolved again in 100 mL of water, once again precipitated in isopropanol (600 mL), filtrated and rinsed with isopropanol and vacuum-dried (2·10⁻³ mbar). To remove all byproducts, the polymer was purified using 12-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a dark brown solid (2.89 g, M=652.64 g/mol Na⁺-form=4.43 mmol) was obtained. A portion of the sodium salt (batch 38) (approx. 1.0 g) was transformed by means of an ion exchanger (Dowex® Marathon® C) into the H⁺-form.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

insoluble in aqueous 1M-NaCl solution, methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone, ethyl acetate, trifluoroacetic acid.

Exchange capacity: experimental: 3.190 mmol/g (313.48 g/mol) for H⁺-form theoretical: 3.102 mmol/g (322.36 g/mol) assumption: 1.0 H₂O/SO₃H theoretical: 3.286 mmol/g (304.34 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.4974 g/cm³ for H⁺-form Analysis: experimental: C: 36.78, H: 3.94, S: 20.76, Cl: 0.79 theoretical: C: 47.35, H: 2.65, S: 26.33, Cl: 0.00 with 0.0 H₂O/SO₃H theoretical: C: 37.39, H: 4.45, S: 20.79, Cl: 0.00 with 4.5 H₂O/SO₃H theoretical: C: 37.05, H: 4.41, S: 20.60, Cl: 0.91 with 4.5 H₂O/SO₃H and polymerization rate = 10, Cl end groups

¹H-NMR (300 MHz, DMSO-d₆): δ=8.08 (s, 2H, CH), 7.56 (d, 2H, CH, J_(HH)=8.4 Hz), 7.47 (d, 4H, CH, J_(HH)=8.2 Hz), 7.13 (d, 4H, CH, J_(HH)=8.2 Hz), 6.74 (d, 2H, CH, J_(HH)=8.4 Hz).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=158.1 (s), 145.9 (s), 144.5 (s), 138.5 (s), 136.9 (s), 128.3 (s), 127.7 (s), 126.6 (s), 125.9 (s), 121.3 (s).

Molecular weight: M_(n)=2217, M_(w)=3402 g/mol, D=1.5346 (GPC) for Na⁺-form

II. Oxidation:

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,4-phenylene-oxide): 1.55 g (2.37 mmol, M=652.64 mol/g) finely mortared solid from the above reaction were suspended in 50 mL of pure acetic acid and 5 mL of concentrated sulfuric acid. The dark brown reaction mixture was heated to 55° C. while slowly dripping in 4 mL of a 36% hydrogen peroxide solution (approx. 40 mmol H₂O₂). This mixture was agitated for 5 h at 55° C., during which time the solid became gradually lighter. Subsequently, the mixture was briefly heated to 110° C. to remove any excess peroxide. Then the mixture was diluted with 150 mL of pure acetic acid. The pale yellow solid was filtrated and rinsed several times in pure acetic acid. To remove all byproducts, the polymer was purified using 48-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a light brown solid (1.45 g, M=672.68 g/mol=2.16 mmol) was obtained.

Solubility:

Soluble in water, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc), concentrated sulfuric acid;

insoluble in methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 1.930 mmol/g (518.13 g/mol) for H⁺-form theoretical: 1.936 mmol/g (516.49 g/mol) assumption: 10.0 H₂O/SO₃H theoretical: 2.973 mmol/g (336.34 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.662 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.47 (s, 2H, CH), 8.44 (d, 2H, CH, J_(HH)=7.7 Hz), 8.11 (d, 2H, CH, J_(HH)=7.7 Hz), 7.84 (d, 4H, CH, J_(HH)=7.9 Hz), 7.17 (s, 5H, H₂O), 7.04 (d, 2H, CH, J_(HH)=7.9 Hz).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=159.9 (s), 149.5 (s), 144.1 (s), 143.4 (s), 136.9 (s), 133.9 (s), 132.2 (s), 129.8 (s), 129.7 (s), 119.3 (s).

EXAMPLE 7 Synthesis of a poly(sulfonic acid phenylene sulfone) with Variable Exchange Capacity Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,4-phenylene-oxide-1,4-phenylene-sulfone-1,4-phenylene-oxide-1,4-phenylene-sulfone-1,4-phenylene-sulfone) with n=0.7

${{EW}\left( {{sPS}\text{-}V} \right)} = \frac{{440.42\mspace{14mu} n}\; + \;{744.81\left( {1 - n} \right)}}{2\mspace{14mu} n}$ ${{EW}\left( {{sPSS}\text{-}V} \right)} = \frac{{408.43\mspace{14mu} n}\; + \;{712.82\left( {1 - n} \right)}}{2\mspace{14mu} n}$ N 1.0 0.9 0.8 0.7 0.6 0.5 IEC(sPS-V) 4.5411 3.8228 3.1917 2.6329 2.1346 1.6874 EW(sPS-V) 220.21 261.59 313.31 379.81 468.48 592.62 MW(sPS-V) 440.42 470.86 501.30 531.74 562.18 592.62 IEC(sPSS-V) 4.8968 4.1015 3.4093 2.8014 2.2634 1.7837 EW(sPSS-V) 204.22 243.82 293.32 356.96 441.82 560.63 MW(sPSS-V) 408.43 438.87 469.31 499.75 530.19 560.63 MW(sPSS-V-Na) 452.39 478.43 504.48 530.52 556.56 582.61 I. Polymerization:

Poly(1,4-phenylene-sulfone-1,4-phenylene-sulfide-1,4-phenylene-sulfone-1,4-phenylene-oxide-1,4-phenylene-sulfone-1,4-phenylene-oxide-1,4-phenylene-sulfone-1,4-phenylene-sulfide): The polymerization was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet, a magnetic agitator and a Dean-Stark trap provided with a cooler. 3.7680 g (7.35 mmol) of disodium-3,3′-disulfonate-4,4′-difluoro-diphenyl-sulfone-trihydrate, 2.2650 g (3.15 mmol) of bis-(4-fluorophenyl-sulfophenyloxophenyl)sulfone, 0.8199 g (10.50 mmol) of sodium sulfide (Na₂S) and 0.861 g (10.50 mmol) of dried sodium acetate were filled into this flask. This mixture was vacuum-dried for 2 h at 70° C. (2·10⁻³ mbar). Then, 18 ml of dried 1-methyl-2-pyrrolidone (NMP) and 40 ml of dried toluene were added under argon, and the reaction mixture was heated in an oil bath for 4 h until it had reached 150° C., in order to remove all traces of water (dehydrator). The toluene was then removed by draining the Dean-Stark trap (distilled) and the reaction was continued for 15 h at 190° C. After cooling it to room temperature, the dark green suspension was slowly dripped into isopropanol (600 mL) to precipitate the polymer. The dark green precipitate was filtrated and rinsed with isopropanol. The product was then suspended in 200 mL of water; to remove all byproducts, it was purified using 24-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar) a dark brown solid (2.44 g, M=530.52 g/mol Na⁺-form=4.60 mmol) was obtained.

Solubility:

Soluble in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc); insoluble in water (swelling), methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

¹H-NMR (300 MHz, DMSO-d₆): δ=8.21 (s, CH), 7.89, 7.86, 7.72, 7.69, 7.44, 7.17 (without assignment of signals), 3.25 (s, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=160.1 (s), 148.7 (s), 141.7 (s), 141.1 (s), 140.9 (s), 139.0 (s), 137.3 (s), 136.8 (s), 135.0 (s), 132.1 (s), 130.9 (s), 129.3 (s), 128.9 (s), 127.0 (s), 120.6 (s), 117.0 (s).

II. Oxidation:

Sulfonated poly(1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,4-phenylene-sulfone-1,4-phenylene-oxide-1,4-phenylene-sulfone-1,4-phenylene-oxide-1,4-phenylene-sulfone-1,4-phenylene-sulfone) 1.56 g (2.94 mmol) finely mortared solid from the above reaction were suspended in 30 mL of pure acetic acid and 2.7 mL of concentrated sulfuric acid. The dark brown reaction mixture was heated to 55° C. while slowly dripping in 1.5 mL of a 36% hydrogen peroxide solution (approx. 15 mmol H₂O₂). This mixture was agitated for 3 h at 55° C., during which time the solid became gradually lighter. Subsequently, the mixture was briefly heated to 110° C. to remove any excess peroxide. Then the mixture was diluted with 150 mL of pure acetic acid. The slightly brownish solid was filtrated and rinsed several times in pure acetic acid. To remove all byproducts, the polymer was purified using 48-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a slightly brownish solid (0.977 g, 1.84 mmol, M=531.74 g/mol) was obtained.

Solubility:

Soluble in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc); insoluble in water (swelling), methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 1.595 mmol/g (627.00 g/mol) for H⁺-form theoretical: 1.786 mmol/g (559.96 g/mol) assumption: 10.0 H₂O/SO₃H theoretical: 2.633 mmol/g (379.81 g/mol) assumption: 0.0 H₂O/SO₃H Density: 1.570 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆) δ=8.33, 8.16, 8.09, 7.99, 7.87 (strong signal), 7.64, 7.49, 7.39, 7.15 (strong signal) (all signals without assignment), 4.48 (s, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆) δ=160.8 (s), 160.1 (s, strong signal), 159.8 (s), 148.6 (s), 147.7 (s), 146.8 (s), 144.7 (s) 143.8 (s), 143.4 (s), 142.5 (s), 142.1 (s), 137.3 (s, strong signal), 135.4 (s), 132.9 (s), 131.5 (s), 130.9 (s, strong signal), 130.1 (s), 129.6 (s), 129.0 (s), 128.6 (s), 128.1 (s), 127.7 (s), 120.9 (s), 120.6 (s, strong signal), 116.9 (s).

EXAMPLE 8 Synthesis of a poly(sulfonic acid phenylene sulfone ketone) with Variable Exchange Capacity Sulfonated poly(1,4-phenylene-ketone-1,4-phenylene-sulfone)

EXAMPLE 9 Synthesis of a block-co-polymer Consisting of a poly(sulfonic acid phenylene sulfone) and a αω-dihydroxy-component HO—W—OH

During the reaction with alkali sulfide, the reaction solution will contain additives such as alkali metal carboxylates (e.g. sodium acetate, lithium acetate), alkali metal carbonates (e.g. lithium carbonate), alkali metal sulfonates, lithium borate, lithium chloride.

Preferred solvents for the reaction with HO—W—OH are aprotic, polar, high-boiling solvents, such as 1-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethyl acetamide (DMAc), sulfolane, diphenyl sulfone, 1,3-dimethyl-2-imidazolidinone.

The reaction temperature is typically 100-250° C., preferably 140-200° C.

The reaction time is typically 5-24 h, preferably 12-18 h.

EXAMPLE 10 Synthesis of a block-co-polymer Consisting of a poly(sulfonic acid phenylene sulfone) and a αω-dihalogen-component Hal-W-Hal

A preferred reaction temperature for the reaction with sodium hydride (NaH) in DMF is 0-30° C.

The reaction time is typically 1-24 h.

EXAMPLE 11 Synthesis of poly(sulfonic acid 1,4-phenylene-sulfone)

I. Sulfonation of poly(1,4-phenylene-sulfide):

Sulfonated poly(1,4-phenylene-sulfide): The sulfonation was carried out in a heated 100 mL round flask filled with argon and equipped with an argon inlet and a magnetic agitator. In this flask, 4.04 g (37.4 mmol) of poly(1,4-phenylene-sulfide) (Aldrich, M_(n)=15000, M=108.15 g/mol) were suspended in 50 mL of concentrated sulfuric acid. Under strong agitation, 10 mL of a 60% SO₃ solution in sulfuric acid (oleum, approx. 150 mmol SO₃) were slowly dripped into this suspension, resulting in a dark green solution. This solution was agitated for 12 h at room temperature. The solution was then slowly poured into 400 mL of pure acetic acid (cooled to 0° C. in an ice bath), during which process the polymer was precipitated as a greenish solid. This solid was filtrated and vacuum-dried (2·10⁻³ mbar) for 2 h. A slightly greenish solid was obtained.

Solubility:

Soluble in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc); insoluble in water (swelling), methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Density: 1.720 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=7.8-7.4 (br m), 7.19 (br m), 3.72 (s, H₂O).

II. Oxidation of Sulfonated poly(1,4-phenylene-sulfide):

Sulfonated poly(1,4-phenylene-sulfone): 5.0 g (26.6 mmol, M=188.21 mol/g) finely mortared solid from the above reaction were suspended in 100 mL of pure acetic acid and 10 mL of concentrated sulfuric acid. The dark brown reaction mixture was heated to 55° C., and then 10 mL of a 36% hydrogen peroxide solution (approx. 100 mmol H₂O₂) were slowly dripped in. This mixture was agitated for 12 h at 55° C. Subsequently, the pale yellow mixture was briefly heated to 110° C. to remove any excess peroxide. The mixture was then diluted with 300 mL of pure acetic acid, and the solid was filtered out, to be suspended in 100 mL of water. To remove all byproducts (sulfuric acid, acetic acid), the suspension was purified using 72-hour dialysis (dialysis tube by Sigma-Aldrich, molecular weight exclusion=8000); after removing the solvent and vacuum-drying at 50° C. (2·10⁻³ mbar), a pale yellow solid (4.5 g, M=220.21 g/mol) was obtained.

Solubility:

Soluble in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP), N,N′-dimethyl acetamide (DMAc); insoluble in water (swelling), methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 1.780 mmol/g (561.80 g/mol) for H⁺-form Sulfonation rate = 29.1% (n = 0.291) assumption: 0.0 H₂O/SO₃H Sulfonation rate = 34.2% (n = 0.342) assumption: 4.0 H₂O/SO₃H Density: 1.636 g/cm³ for H⁺-form

¹H-NMR (300 MHz, DMSO-d₆): δ=8.1 (br m), 5.18 (s, H₂O).

¹³C-NMR (75.5 MHz, DMSO-d₆): δ=145.7 (s), 145.2 (s), 139.8 (s), 134.6 (s), 130.2 (s), 128.7 (s).

III. Oxidation of Sulfonated poly(1,4-phenylene-sulfide) with IEC=1.6 mmol/g:

Sulfonated poly(1,4-phenylene-sulfone): 5.00 g (0.04 mol, M=124.2 mol/g, IEC=1.6 mmol/g) finely mortared sulfonated poly(1,4-phenylene-sulfide) from a different batch were suspended in 300 mL of pure acetic acid and 15 mL of concentrated sulfuric acid. Then, 12 mL of a 30% hydrogen peroxide solution (approx. 0.12 mol H₂O₂) were slowly dripped in. This mixture was agitated for 36 h at RT. The white solid was then filtrated and rinsed in 200 mL of water. Afterwards, it was vacuum-dried for 12 h at 60° C. The result was a white solid (5.73 g, 91.1%) that was virtually insoluble in all solvents used. A film formation from hot NMP was not possible.

Solubility:

Negligible solubility in hot 1-methyl-2-pyrrolidone (NMP). Insoluble in water, DMSO, methanol, ethanol, isopropanol, toluene, tetrahydrofuran (THF), chloroform, acetone.

Exchange capacity: experimental: 0.96 mmol/g (1041 g/mol) for H⁺-form theoretical 1.28 mmol/g (781 g/mol) assumption: 0.0 H₂O/SO₃H

Analog to the reactions described in EXAMPLE 11, additional polymers with varying exchange capacities (sulfonation rate) were produced using various ratios of the initial polymer poly(1,4-phenylene-sulfide) and oleum (SO₃). The reaction conditions were analog.

The following publications contain subject matter that is incorporated herein by reference:

LITERATURE OVERVIEW

A general overview of the state of fuel cell technology is provided in Part 3 of the Handbook of Fuel Cells—Fundamentals, Technology and Applications, Vol. 3 (Eds. W. Vielstich, A. Lamm, H. A. Gasteiger), John WILEY & Sons, 2003. An overview of membrane materials for fuel cells can be found in the reviews by Q. Li, R. He, J. O. Jensen, N. J. Bjerrum Chem. Mater. 2003, 15, 4896 and M. A. Hickner, H. Ghassemi, Y. S. Kim, J. E. McGrath Chem. Rev. 2004, 104, 4587; a glimpse into the correlations between structure, morphology and transport processes in membranes for fuel cells is provided in the review by K. D. Kreuer, S. J. Paddison, E. Spohr, M. Schuster Chem. Rev. 2004, 104, 4637.

Polymers with the structural element —SO₂—Ar(SO₃H)_(n)—SO₂— (Ar=aromate, n=1-4) have not been not described according to CA (Chemical Abstracts). There is, however, a number of publications and patents on polymers with the structural element —SO₂—Ar(SO₃H)—O— (poly(arylene ether sulfones)), e.g. in F. Wang, M. Hickner, Y. S. Kim, T. A. Zawodzinski, J. E. McGrath J. Membr. Sci. 2002, 197, 231), wherein the aromate carrying the sulfonic acid group is surrounded by a sulfone group —SO₂—, as well as an ether group —O—. Instead of the ether group, analog polymers with a thioether group (sulfide group) —S— have also been described: poly(arylene thioether sulfones) or poly(arylene sulfide sulfones) with the structural element —SO₂—Ar(SO₃H)—S—, e.g. in T. D. Dang, Z. Bai, M. J. Dalton, E. Fossum Polymer Preprints 2004, 45, 22; Z. Bai, L. D. Williams, M. F. Durstock, T. D. Dang Polymer Preprints 2004, 45, 60; K. B. Wiles, V. A. Bhanu, F. Wang, M. A. Hickner, J. E. McGrath Polymer Preprints 2003, 44, 1089; F. Wang, J. Mecham, W. Harrison, J. E. McGrath Polymer Preprints 2000, 41, 1401; K. B. Wiles, V. A. Bhanu, F. Wang, J. E. McGrath Polymer Preprints 2002, 43, 993; K. B. Wiles, C. M. de Diego, J. E. McGrath Polymer Preprints 2004, 45, 724.

The synthesis of these polymers takes place by means of polycondensation of sulfonated dichlorodiphenylsulfone or difluorodiphenylsulfone with thiobisbenzenethiol. An initial mention of the sulfonated monomer of dichlorodiphenylsulfone or difluorodiphenylsulfone can be found in the patent of L. M. Robeson, M. Matzner U.S. Pat. No. 4,380,598 (1983), or in the publication by M. Udea, H. Toyota, T. Ochi, J. Sugiyama, K. Yonetake, T. Masuko, T. Teramoto J. Polym. Sci., Polym. Chem. 1993, 31, 853. Consequently, a number of polymerizations based on sulfonated monomers of this kind were described, e.g. in F. Wang, M. Hickner, Q. Ji, W. Harrison, J. Mecham, T. A. Zawodzinski, J. E. McGrath Macromol. Symp. 2001, 175, 387 and F. Wang, M. Hickner, Y. S. Kim, T. A. Zawodzinski, J. E. McGrath J. Membr. Sci. 2002, 197, 231 and W. Harrison, F. Wang, J. B. Mecham, V. Bhanu, M. Hill, Y. S. Kim, J. E. McGrath J. polym. Sci., Polym. Chem. 2003, 41, 2264 and F. Wang, J. Li, T. Chen, J. Xu Polymer 1999, 40, 795 and F. Wang, T. Chen, J. Xu Macromol. Chem. Phys. 1998, 199, 1421.

In addition, unsulfonated polymers with the structural element —SO₂—Ar—SO₂— (Ar=aromate, unsulfonated) are the subject of several patents, for example in J. Studinka, R. Gabler, Polyarylene sulphonates from sulphonated polyarylene sulphide by two-stage oxidation in acid medium DE Patent 1938806A1 (1970), and in U.S. Pat. Nos. 6,020,442 (2000), 6,013,761 (2000), 5,496,916 (1996), 5,496,917 (1996) and several publications such as D. R. Robello, A. Ulman, E. Urankar Macromol. 1993, 26, 6718 and H. M. Colquhoun, P. Aldred, F. H. Kohnke, P. L. Herbertson, I. Baxter, D. J. Williams Macromol. 2002, 35, 1685.

One publication on the mechanism of sulfonation at the aromate is J. O. Morley, D. W. Roberts J. Org. Chem. 1997, 62, 7358-7363.

SPECIAL REFERENCES

-   [1] T. D. Dang, Z. Bai, M. J. Dalton, E. Fossum Polymer Preprints     2004, 45, 22 -   [2] Z. Bai, L. D. Williams, M. F. Durstock, T. D. Dang Polymer     Preprints 2004, 45, 60 -   [3] K. B. Wiles, V. A. Bhanu, F. Wang, M. A. Hickner, J. E. McGrath     Polymer Preprints 2003, 44, 1089 -   [4] F. Wang, J. Mecham, W. Harrison, J. E. McGrath Polymer Preprints     2000, 41, 1401 -   [5] K. B. Wiles, V. A. Bhanu, F. Wang, J. E. McGrath Polymer     Preprints 2002, 43, 993 -   [6] K. B. Wiles, C. M. de Diego, J. E. McGrath Polymer Preprints     2004, 45, 724 -   [7] J. Studinka, R. Gabler (Uitikon-Waldegg, C H), Polyarylene     Sulphonates from Sulphonated Polyarylene Sulphide by Two-Stage     Oxidation in Acid Medium DE 1938806A1 (1970) -   [8] D. Fleischer, H. Strutz, J. Kulpe, A. Schleicher (Ticona GmbH,     Germany), Oxidized Polyarylene Sulfides U.S. Pat. No. 6,020,442     (2000) -   [9] D. Zierer, H. Scheckenbach (Ticona GmbH, Germany), Oxidation of     Polyarylene Sulfides U.S. Pat. No. 6,013,761 (2000) -   [10] D. Fleischer, H. Strutz, J. Kulpe, A. Schleicher (Hoechst     Aktiengesellschaft, Germany), Process for Oxidizing Polyarylene     Compounds Containing Thioether Groups U.S. Pat. No. 5,496,916 (1996) -   [11] D. Fleischer, H. Strutz, J. Kulpe, A. Schleicher (Hoechst     Aktiengesellschaft, Germany), Two-Stage Oxidation of Polyarylene     Sulfides U.S. Pat. No. 5,496,917 (1996) 

1. A sulfonated poly(arylene) containing exclusively recurring structural element(s) of formulas —[—Ar₁(SO₃M)_(n)-X—]— and —[—Ar₂(SO₃M)_(n)-Y—]—, wherein X and Y are each —SO₂— and Ar₁ and Ar₂, which are either identical or different from each other, represent an aromatic or heteroaromatic ring system with 5-18 ring atoms; wherein the aromatic or heteroaromatic ring system, in addition to SO₃M and X and Y, does not include additional substituents; M represents a monovalent cation and n is an integral number between 1 and 4; M and n can be identical or different in various structural elements, independently of each other, and has a molecular weight of 2,000 to 2,000,000.
 2. The sulfonated poly(arylene) according to claim 1, wherein Ar₁ and Ar₂ are phenylene, and which contains exclusively one of structural elements I, II or III:

wherein X, Y, M are defined as in claim 1 and n is
 1. 3. The sulfonated poly(arylene) according to claim 2, which is the homopolymer poly(sulfonic acid-1,4-phenylen sulfone), obtained by polycondensation of the sulfonated aryl monomer 3,3′-disulfonate-4,4′halo-diphenylsulfone and alkali disulfide and subsequent oxidation of the resulting sulfonated poly(arylene sulfide sulfone).
 4. The sulfonated poly(arylene) according to claim 1, wherein the cation M is selected from the group consisting of Li⁺, Na⁺, K⁺, NR₄ ⁺, PR₄ ⁺ and H⁺, wherein R is an organic residue.
 5. The sulfonated poly(arylene) according to claim 1, wherein n equals
 1. 6. A sulfonated poly(arylene) containing exclusively recurring structural elements of formulas 1) —[—Ar₁(SO₃M)_(n)-X—]— and —[—Ar₂(SO₃M)_(n)-Y—]—, wherein X and Y are each SO₂, Ar₁ and Ar₂ which are either identical or different from each other, represent an aromatic or heteroaromatic ring system with 5-18 ring atoms and n is 1, and 2) —[Ar₃—Z—]—, wherein Ar₃ represents an aromatic or heteroaromatic ring system with 5-18 ring atoms without SO₃M substituents, Z is —O—, and can be identical or different in different elements —[—Ar₃—Z—]—, provided that Z is not bound to a sulfonated ring system of the formula Ar₁(SO₃M)_(n) or Ar₂(SO₃M)_(n).
 7. The sulfonated poly(arylene) according to claim 6, wherein Ar₁, Ar₂ and Ar₃ are each phenylene.
 8. The sulfonated poly(arylene) according to claim 1, having a molecular weight of 10,000 to 1,000,000.
 9. The sulfonated poly(arylene) according to claim 1, embedded in a porous matrix.
 10. The sulfonated poly(arylene) according to claim 1, combined with fiber materials, fillers or other additives.
 11. Membrane material comprising the sulfonated poly(arylene) according to claim
 1. 12. Direct methanol fuel cells comprising the sulfonated poly(arylene) according to claim
 1. 13. Ion-exchanger membranes comprising the sulfonated poly(arylene) according to claim
 1. 14. Materials for electrodialysis, Donnan dialysis, electrolysis, for humidification and dehumidification, or for electromagnetic screening comprising the sulfonated poly(arylene) according to claim
 1. 15. The sulfonated poly(arylene) according to claim 6, wherein the aromatic or heteroaromatic ring systems Ar₁ and Ar₂, in addition to SO₃M and X and Y, do not feature additional substituents, and wherein the aromatic or heteroaromatic ring system Ar₃, in addition to X, Y and Z, does not feature additional substituents.
 16. The sulfonated poly(arylene) according to claim 15, wherein Ar₁, Ar₂ and Ar₃ are each phenylene.
 17. The sulfonated poly(arylene) according to claim 6, wherein Z is —O—.
 18. The sulfonated poly(arylene) according to claim 15, wherein Z is —O—. 